VOLUME XIX

.-

, I

WINTER 1983

WINTER 1983
Volume 19 Number 4

TABLE OF CONTENTSFEATUREARTICLES191

Engraved Gems: A Historical Perspective
Fred L. G r a y

202

Gem Andradite Garnets
Carol M.Stoclzton a n d D. V i n c e n t M a n s o n

209

The Rubies of Burma: A Review of the Mogok Stone Tract
Peter C . Keller

NOTES
AND NEWTECHNIQUES
. ,

220

Induced Fingerprints
John I, Koivula

228

Cobalt Glass as a Lapis Lazuli Imitation
George Bosshart

REGULARFEATURES

232
238
246
249
252

Gem Trade Lab Notes
Gemological Abstracts
Gem News
Book Reviews
Suggestions for Authors

253

Index to Volume 19, Numbers 1-4
ABOUT THE COVER: Engraved gems are almost as old as civilization itself. Fred Gray provides an introduction to their complex history in this issue. Illustrated on the cover are someof the engraved stones used from as early as 3000 B.C. to as recently as the 19th century: (1)Egyptian scarab o f Amenhotep 111, 1400 B.C.; (2) Hittite turquoiseseal, 1500B.C.; (3) Gnostic
seal with inscription, 4th century A. D.; (4)pre-Columbian clay cylinder seal from Esn~eralda,
Equador; (5) Sassanid inscribed seal o f green jasper, 6th century A. D.;(6) Sassanid inscribedseal of cor~~elian,
6th century A.D.; (7) lapis lazuli scarab, 1300 B.C.; (8)Phoenician jasperseal, 900 B.C.; (9) Roman carnelian seal with gold band, 1st century A D . ; (10) Roman seal
ring, bronze, 1st-3rd century B.C.; (11) Austrian rock-crystal seal, 19th century; (12)sardonyx
cameo with bird, Roman, 1st-3rd century A.D.; (13) Roman jasper seal with cupid, 1st-2nd
century A.D.; (14) chalcedony seal with cherub, 7th century B.C.; (15) Roman seal ring, gold
andcarnelian, 1st century A.D.; (16) Sumerian cuneiform tablet, 1500-1200B.C.; (17)steatite
cylinder seal, 3000-2500 B.C.; (18)Assyrian cylinder seal, chalcedony, 200 B.C.; ( 1 9) green
jasper cylinder seal, 2100-1900 B.C.; (20) Babylonian hematite cylinder seal, 1900-1300 B.C.
The stones are courtesy of Barakat, Rodeo Collection, Beverly Hills, CA.
Photo 01983 Harold a) Erica Van Pelt-Photographers, Los Angeles, CA.
Typesetting for Gems & Gemology is by Scientific Composition, Los Angeles, CA. Color separations are b y Effective Graphics, Compton, CA. Printing is b y Waverly Press, Easton, MD.

Q1984 Gemological Institute of America

All rights reserved.

ISSN 0016-626X

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ENGRAVED GEMS:A HISTORICAL PERSPECTIVE
By Fred L. GrayF

Such innocuous events as the creation of the
pre-gummed envelope and the m o d e mpostal system contributed t o the demise of
the engraved gem seal. During thethousands of years that the seal served as
man's most important mark of identification, however, gem engravingreigned as oneof his most significant art forms. This article
traces the-history of engraved gems fromprimitive amulets through cylinder seals,
scarabs, scaraboids, and ringstones, to themore recently introduced cameos. Also discussed is the engraving process itself, h o w
to evaluate an engraved gem, and more
recent developments i n the materials andmethods used to engrave gems.

or virtually thousands of years in the early days ofWestern civilization, the words gem and engraved
gem were virtually synonymous. The earliest engraved
gems evolved from amulets on which gods as well as
everyday images such as animals were carved. As thesecarved charms came to symbolize the owner or wearer as
an individual, they developed into seals with which hemight mark his property or, as civilization became moresophisticated, he might use as tools in barter and trade.
These seals became the personal mark, or "signature," of
their owners. As such, they were often worn on the clothing of the bearer, attached to a thong around his wrist orneck or, in later years, mounted in a ring. With time, theornamental value of the seal began to equal its utilitarianvalue. Eventually, a form of engraving gems for purely
ornamental value emerged-and from the Hellenistic period of ancient Greece to the present, cameos have played
an important role in the engraver's art.
The purpose of this article is to provide a historical
overview of engraved gems, including an introduction to
the different types as well as the techniques and materials
used to produce them. Although particular attention is
given to the early history of gem engraving, especially therole of seals, we will also take a brief look at the current
status of engraved gems and important considerations intheir evaluation.

ABOUT THE AUTHORINTAGLIO AND CAMEO
Gem engraving is a miniaturistic art form whereby designs
are cut into or on the surface of a gem. The outstanding
feature of this type of carving is the small scale of the art:
gem engraving is done most often on a surface less than one
inch (2.5 cm) in diameter. Also known as glyptic (from theGreek wordglyptos, meaning carved) art, gem engraving isoften distinguished by the great attention to detail accomplished on such a small surface.

Fred Gray, a former instructor at the Gemological
Institute of America, is currently a gemologist with
Richter's of Nashville, Tennessee.
Acknowledgments: The author wishes to thankMichael Stubin, Joel Malter (of Joel L. Malter &Company, Inc.), Manfred Wild, Gerhard Becker,
Harold and Erica Van Pelt, and Dr. Jiri Frel (curatorof antiquities at the J. Paul Getty Museum) for their
help in the preparation of this article.

01984 Gemological Institute of America

Engraved Gems

GEMS & GEMOLOGY

Winter 1983

191

INTAGLIOCAMEO

Figure 1. The intaglio (used primarily for seals)
and cameo are the oldest forms ofengraved gems.

For the most part, engraved gems can be divided into two distinct types: intaglio and cameo(see figure 1).An intaglio is made by grinding awaymaterial below the surface of the gem, leaving an
inverse image. Detail is achieved by varying thedepth of the engraving. A cameo is the opposite of
an intaglio: that is, the subject is sculpted above
the surface of the gem, appearingin relief on stones
usually of two or more different-colored layers.
Most cameos utilize several layers of material toincrease the definition of the carving. Anothertype of engraved gem occasionally encountered isthe chevet (alsocalled chevee or cuvette), in whicha raised figure rests in a background sunk below
the surface. Because the chevet is a relatively
modern development, it will not be discussed further here.
THE ENGRAVINGPROCESSThe earliest gemstone engraving was accomplished simply by drawing a piece of hard stone ormetal against a softer material to produce grooves.
The results may have been adequate, but the finished pieces lacked subtlety in design and were
often very crude. This simple technique was eventually followed by the use of a drill to form crude
round depressions. The earliest drill was a simple
hand-held device driven by a bow that was moved
back and forth (figure 2). The drill shaft was made192

Engraved Gemsof wood, to which a small piece of flint was attached as a bit (Sutherland, 1965; King, 1885).The
vertical drill, which was very difficult to holdsteady, was eventually replaced by a horizontal
version, which allowed better control of the workin progress by freeing the hands to manipulate
the gem.
Fine-grained rock (serpentine, soapstone, etc.)
was often used for the earliest engraved seals because of ease of carving (see cover). We do notknow when metal points replaced the stone points
on the drill (although King, 1882, suggests that it
may have been as early as 2000 B.C.), but we doknow that metal points used in conjunction withemery or another hard powder (added as the drill
revolved to do the actual abrading) enabled thecutting of harder materials such as jasper and carnelian (again, see cover). Varieties of chalcedony
were overwhelmingly favored because of theiravailability, the predictability of their lapidary behavior, and their great strength, which helped assure the carver that he would not break the piece
before he was through (John Sinkankas, personalcommunication, 1983).
When the early glyptic artists replaced theirdrill bits of stone with metal tools and cutting
wheels, they had essentially the same equipmentthat engravers use today (Gerhard Beclzer, personalcommunication, 1983).For convenience and to increase the speed of the drill, contemporary
craftsmen use machine instead of man power. Another modem development is the replacement ofemery by far faster-cutting diamond powder.
The actual engraving process is exacting andlaborious. Because of the small scale involved, it is
one of the most difficult of the sculpting arts. For
an intaglio, where the design is to be sunk below
the top of the gem, the surface is usually given its
final polish at the outset, and the design drawn onthat surface. The engraving begins with larger
cutting tools: wheels, and ball- and oval-shaped
bits. In the later stages, tools as small as the head ofa pin are used for the detail work. Lastly, the actualengraving may be polished or textured, dependingon the detailing desired (Renton, 1896).
It is interesting to note that magnification is
not commonly used during the engraving process.
The slurry of polishing compound obscures thecarving in progress. The hands and cutting tools
also make direct observation of the work difficult.
The cutter must rely mainly on the feel of thecarving to execute the design. To check his prog-

GEMS & GEMOLOGY

Winter 1983

Figure 2. This Egyptian drawing
shows an early technique for drilling
holes in stone which involved thebow drill. The bow caused the drill bit
to revolve, thereby boring a hole into
the sione. Modern historians surmisethat this same equipment was also
probably used to engrave gems.

ress, however, the craftsman constantly presses
the stone into clay and examines the design inpositive with a loupe. We have little information
to suggest that magnification of any form was usedby ancient engravers, although a current theory
holds that these early craftsmen commonly were
myopic, thereby naturally possessing better vision
at a close'range (Michael Stubin, personal communication, 1982).

'

THE HISTORY OF
ENGRAVED GEMS
The Introduction of the Seal. The history of stone
engraving is as old as organized societies, having
originated when the first congregations of man
developed socially and economically to a point
where there was a need for sealing property.
Worm-eaten wood pressed into clay was one of theearliest means, as the random pattern of these bits
made each seal unique (King, 1885).
The engraving of harder materials specificallyto serve as individual seals was the next logicalstep. An important factor in this progression wasthat prehistoric man had used and worn crudely
carved amulets, decorated with the animals andreligous figures so central to his world. As theconcept of personal property-and later those of
trade, taxes, banking, and the like-required theuse of a personal mark, the evolution of these amulets into seals was a natural development (Sutherland, 1965).For convenience, the seals were often
worn on the owner's clothing or at the neck orwrist. With time, their function became
ornamental-as jewelry-as well as utilitarian andreligious. The widespread acceptance of seals is

Engraved Gems

undoubtedly due to the fact that they satisfied somany needs for newly civilized man.
The earliest seals were probably introduced
between 6500 and 6000 B.C. in the neolithic cities
of Mesopotamia (Sutherland, 1965). These primitive seals are extremely varied in shape and material. Most were made from fired clay, but locallyavailable soft stones were also used. Such seals
were shaped into cones, rectangular tablets,bean-like forms, and the like: Vast numbers ofthese have been found, usually with religious motifs or with simple geometric designs.
Cylinder Seals and Scarabs. The first importantgroup of engraved seals were the cylinder seals (seefigure 3 and the cover), which made their appearance in the river valleys of southern Mesopotamia
around 3300 B.C. (Wiseman, 1956), or approximately the same time that writing was first employed as a means of communication. Cylinder
seals were used to sign documents, to seal goods
for barter or tax purposes, and as trademarks on
objects such as pottery. Their shapes made them
ideally suited for rolling around the openings ofjars, bottles, sacks, and other containers to discourage tampering. Locally obtained materials
such as hematite, serpentine, jasper, and chalcedony were most commonly used to make cylinder
seals, but the highly prized lapis lazuli was occasionally obtained via trade (Wiseman, 1956).
The Egyptians also used the cylinder seal, butthey eventually created a seal that was both ofgreater religious significance and served theirneeds better: the scarab (figure 4). Whereas thecylinder was ideally suited for sealing large ob-

GEMS & GEMOLOGY

Winter 1983

193

Figure 3. The cylinder seal represents the first important group of seals used by man. An inverse
image was engraved on a cylindrical pieceof stoneso that i t could be rolled out along wet clay, wax, orother impressionable substance to produce a positive image. This Assyrian cylinder seal, madeof chalcedony, dates from approximately 2000 B.C. I t measures 34 m m long x 17 m m i ndiameter. Like most cylinder seals, it has a hole going through the middle lengthwise
to accommodate a string or thong for wearing by its owner. Photo 01983 Harold
and Erica Van Pelt.

jects, the scarab was more appropriate for stamping paper documents made from the papyrus indigenous to Egypt.
The scarab seal took its convex shape from thescarab beetle, which symbolized the sun god andeternity in ancient Egypt. On the flat bottom side,
the artisan engraved hieroglyphic characterswhich served as the bearer's mark (see the large
white stone on the cover). Most early scarab seals
were made of soft materials such as faience, aglazed earthenware pottery. In later periods, hardstones such as carnelian, rock crystal, and amethyst were more often employed. According to Ball
(1950),Egypt was the world's greatest producer ofgems from approximately 3200 to 200 B.C.

The Classical Age: Scaraboid, Ringstone, andCameo. Seals were produced and used most intensively during the classical period of ancient Greece
and Rome (approximately500 B.C. to 400 A.D.].By
this time, the role of engraved stone seals was

Engraved Gems

firmly established; virtually every important culture had adopted them. Although most seals werevery rudimentary, not infrequently they were engraved with great technical skill. The classical artisans of Greece and Rome carried engraving (nowa distinct profession) to a level higher than everseen previously. Their designs were imaginative,
and their technical skills in working with hardstone equal to the demands of their creativity.
Although the earlier cultures of the Minoansand Mycenaeans knew how to work the harder,
more durable materials such as quartz and chalcedony, the destruction of these cultures before
1100 B.C. meant the demise of their technicalknowledge as well. It was not until the seventh
century B.C. that the Greeks learned from the
Phoenicians how to use abrasives on hard stone.
From these great "merchants of the Mediterranean" they also acquired the form of the scarab,which the Phoenicians had adopted previously
from the Egyptians. To this basic shape they added

GEMS & GEMOLOGY

Winter 1983

I

motifs inspired by both events and figures in their
daily lives and by the many colorful legends surrounding the gods they worshipped, making theirseals look distinctively Greelz.
As the Greeks gradually lost interest in thescarab, because it was not relevant to Greek religious symbolism, a new form of seal-the scaraboid-appeared. It was also oval in outline, but thescarab back was replaced by a simple unornamented dome (figure 5).The seal engraving wasstill placed on the flat bottom side which was worn
toward the body.
The scaraboid, like the Greelz scarab, wasmade almost exclusively of chalcedony, a natural
choice because of its durability, availability, andattractiveness. Another important advantage isthat sealing wax does not stick to this cryptocrystalline mineral. The varieties carnelian andsard were used for the earlier scarabs because theirdarker color showed off the engraving of'the beetle
to great advantage. For the new scaraboid, lightermaterial was more often desired, particularly abeautiful blue variety that has more recently
been given, the French name "sapphirine" (Boardman, 1968).
In the third century B.C., Alexander the Great
expanded, the Greek empire into the gem-rich
Eastern countries. The result was a flood of new
gem materials into Greece and later into Rome.
Garnets, amethyst, topaz, beryl, agates, and otherstones were now also available for engraving(Boardman, 1968). Amethyst and garnet became
particular favorites and were often used for thefiner pieces. Interestingly, glass was also highly
valued (Boardman and Vollenweider, 1978).
The Hellenistic period, which spanned the

Figure 4. The highly symbolic scarab beetle
served as the model for the scarab seal that wascommonly employed b y the ancient Egyptians
and was eventually adopted b y other cultures.

Engraved Gems

years between the death of Alexander the Great(323 B.C.) and the conquest of Greece by the Romans (146-39 B.C.), produced several importantinnovations with regard to the glyptic arts. The
first of these was the evolution of the scaraboid
into the ringstone. With the ringstone, the seal was
mounted so that the engraving showed at all times
and was fixed in its setting (figure 6). The finger
ring was soon widely adopted as the ideal mounting for personal signets. Equally important was theacquisition of the diamond point (i.e., minutesplinters of crushed diamond mounted in an irontool) from India (King, 1885). Possessing a hard,
sharp edge, this tool was ideally suited to engraving the fine lines needed to realistically represent
hair and the delicate folds of clothing so admiredby the objective eye of the Hellenistic Greeks andlater the Romans (Richter, 1968).
The Hellenistic period also marked the first
appearance of the modern cameo. During and immediately following the reign of Alexander theGreat, the practice of using a portrait as a seal wasstarted. With the introduction of banded chalcedonies, such as sardonyx, into Greece from its
conquered territories, an engraving form that was
distinctly suited to portraiture-the cameoevolved. Cameos were usually composed of twolayers, a light upper layer against a darker baclzground (figure 71, but complex pieces occasionallyutilized as many as four layers of color. The earliest documented example of a true cameo-theheads of Demetrius Soter and his wife Laodice(162-150 B.C.)-was carved in three layers of sardonyx on a surface that measured only 1'/4 x 1 inch
(King, 1885). Although the cameo had evolved
from the scarab and scaraboid, which had important utilitarian functions, this form of engraving inrelief was for decorative purposes only. Usually,
Figure 5. The simple lines of the scaraboid seal
were preferred b y the ancient Greeks.

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Winter 1983

195

7. A R O ~ U~IaI r n ~~ "' a t i ~dr ~the~ first celltury B.C. or the first century A.D. made fromchalcedony (9 x 1Omm). The subject i s on almost
whimsical rendition of a gorgon. Note that hedetail has been engraved into the white layer ofthe stone, with the darker layer serving as background. Stone courtesy of Michoel Stubin; photob y Mike Havstad.

Fi8u1dFigure 6, This Roman seal from ~11ethird century
A.D. features the head of jupiter engraved in jasper. As was the popular style during this period,
the seal was mounted in a brass ring. Photo andring courtesy of Michael Stubin.

cameos were set in jewelry, especially rings andpendants.
The Roman conquerors greatly admired anything Greelz, and engraved gems were no exception. The earlier Italians) the Etruscansl used theGreelz scarab almost exclusively for their seals(Boardman and Vollenweider, 1978). The later
Romans replaced the scarab with the ringstone andthe signet ring; they also adopted the cameo. Although they did not improve on these models, they
did increase the variety of subjects. While they
contin~~ed
to use the Greelz gods in their designs(figure 81, the Romans added their own gods, alongwith such subjects as chariot races, erotic posesi
whimsical animals, and many other imaginative
creatures and scenes.
The Romans not only were prolific producers
of engraved gems) they were also enthusiastic collectors of the engraved gems of other cultures,
particularly those of Greek origin. As they re-

Ellgraved Gems

turned victorious from their military campaigns,
the commanders would parade their spoils
through the streets of Rome. These displays fueled
an ostentation for jewelry. "Unless you are strewn
with gemsl don't even hope to pass for a wealthyman," wrote Manilius, a Roman poet (Balll 1950).
"Gemsi' and "engraved gemsi1 were virtuallysynonymousl since the great majority of gems perceived to be of value were those that were engraved. Many gems were placed in temples as offerings to the gods and as a display of the Romans1
wealth. Julius Caesar dedicated six cabinets ofgems in the Temple of Venus Genetrix and Marcellusi thereby creating what some experts feel
were the first public museums (Boardman, 1968bI.
The Mediterranean area is poor in gem deposits. Much of the early material! which was
mostly varieties of chalcedony, was piclzed up by
itinerant peddlers traveling in the desert regions.
Egypt was probably the best early sourcei drawing
on their turquoise and, inore rarely, their emerald
and peridot deposits. But with the conquest of theEastern territories! particularly India, by
Alexander the Great and the later Roman militarycommandersi a great profusion of new species andvarieties of gems arrived into the classical world.
Although carnelian and sard continued to be usedpredominantly for engraved seals (1300out of 2600
classical gems in the British Museum are composed of these two varieties of chalcedony),

GEMS & GEMOLOGY

Winter 1983

almandine) rhodolite! and hessonite garnet) amethyst, rock crystall sapphire) bloodstonel jasper,
turquoise, and many other gem materials werealso used for intaglios (see figure 9 and cover).
Emerald from Egypt! Scythia, and possibly theUrals was much appreciated but only occasionallyengraved because of its rarity and fragility. Nevertheless, both Alexander the Great and Cleopatra
favored emerald for their engraved portraits (Ball)
1950).
After the Fall of Rome. With the dismantling of the
Roman empire! so ended the greatest era for theglyptic arts. By the close of the fifth century! gemengraving had virtually passed into extinction(Sutherland) 1965). The Middle Ages contributed
little; the few stones that were engraved were
crudely cut with bold designs that laclzed any subtlety. To satisfy the need for seals, ancient gems
were often remounted in rings with the name of
the bearer carved in the metal surrounding the
Figure 8. A ,Roman intaglio of banded carnelianengraved to represent Athena, the Greek goddessof wisclom, holding a shield and spear, This
ringstone (which melisures 12 x 15 m m ) was engraved i n the first century B.C. Photo and seal
cour&esyof Michael Stubin.

intaglio. For examplel after Charlemagne wascrowned heir to the Caesars by the Pope in 800
A.D.) he made the portrait of the pagan Emperor
Marcus Aurelius Antoninus (88-21 7 A.D.) his
seal. The pagan motifs were reinvested with new
Christian symboIism~effectively sidestepping an
obvious incongruity. Every veiled Roman lady became a Mary Magdalene in the eyes of the Christian wearer; Jupiter was renamed St. John the
Evangelist (Sutherland! 1965).
The average citizen of Western Europe apparently knew and cared little about engraved gems as
seals. Rather, the gems seemed to assume greatest
significance for their purported magical and medicinal powers. For example) the figure of a man
holding a palm branch in his hand) cut in jasper,
was determined to render the wearer "powerful
and acceptable to princesjl' the engraving of ahorse on any stone was indicated as a cure forlunacy; and a lion engraved in garnet would bringriches and honor. The wearer of an Aquarius
carved in green turquoise was assured good luclz inall buying and selling) )'so that buyers shall seek
him1' (Sutherland, 1965).King (1885)cites 42 such
associations. In fact) a common belief during thisperiod was that the stones were not carved by man,but rather were engraved by some force of nature:
man could not have cut such hard material (Anderson) 1981). Although seals continued to be used

Figure 9. This engraving of a sow has been madeon apiece of green quartz, one of the more unusual
gem materials used by the Romans. This 10 x 12.5m m piece has been d a ~ e dto the latter half o f thefirst century A.D.Photo and seal courtesy of
Michael Stu bin.

Engraved Gems

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197

regularlyl most of those newly fashioned weremade from metal rather than stone. With the exception of the few vestiges of Western civilizationthat remained to preserve lznowledge of gem engraving in some fashion-particularly Alexandria
and Byzantium-the art almost vanished.
A Renaissance. With the passage of time and theincreasing civilization of Europe) especially thebroadening of trade and barter) a renewed interestin engraved gems developed. By the 14th century, arevival of stone engraving was apparent, especiallyin Italy. Personal seals! displaying heraldic designs
and Christian motifs in a Gothic style! predominated. These were soon followed in the 15th century by gems engraved with classical subjects. A
renewed interest in anything antique by such important personages as the Medici increased the
popularity of this art form (Morassit 1964). During
this age of personal patronage of art! artisans wereencouraged by the various noble houses and tosome extent the papacy (particularly Pope Paul 11)1417- 1471) to enhance their own slzills and teachothers. Cameos were especially popular during the15th and 16th centuries! since they were much
more conducive to lavish display in jewelry and as
objets d'art than the delicate intaglio. Also during
the Renaissance period! with the influx of finestones-rubies! emeralds! diamonds, and thelike-the art of faceting gems to provide the brilliance and life that made them highly attractive intheir own right developed. Gradually! artisansbegan to specialize in either the glyptic arts or gem
cutting (Sutherland) 1965). The concepts of gem
and engraved gem were no longer inseparable.
An important factor in the renewed popularityof cameos and other engraved gems throughout the
16th and 17th centuries was the discovery of large
deposits of carnelian and agate in the IdarOberstein region of Germany. In conjunction withthese important deposits! the famous lapidarycommunity of Idar-Oberstein was created andnurtured.
Although the renaissance in the glyptic arts
was based on classical designs! the ancient pieces
themselves were not directly copied until the 18th
century, during another resurgence of interest in
all things classical. Napoleon Bonaparte was partially responsible for this neoclassical revival. He
was especially fascinated by engraved gems andeven founded a school for gem engraving. He acquired a great many important pieces as part of theplunder from his conquests. The Vatican was one

198

Engraved Gemsof the reluctant contributors to Napoleon's collection) as this holy seat possessed an importantcollection based on an inheritance from King LouisXV of France (Hinlzs, 1975). Eventually! every
self-styled intellectual, which included much of
the royalty in Europe and others of note! shared
Napoleon's fascination with ancient engraved
gems and sought to establish their own collections. But there was just not enough supply tosatisfy the demand. Falze antiques were created ingreat quantities to fill this gap. This prompted theobservation by C.W. King (1860) that "For every
antique gem of note, fully a dozen of its counterfeits are now in circulationl and often so close is
the imitation as to throw doubt upon the authenticity of the original itself.)'
The downfall that resulted was inevitable. The
leading character in this drama was Prince
Poniatowsl~i~
who had inherited from his uncle!
the last lzing of Poland, an important collection of
154 antique engraved gems that he subsequently
expanded to approximately three thousand pieces;
Following the prince's death in 1839/ his collection was auctioned by Sothebyfs in an event thatdrew buyers from all over the world. Shortly after
the sale, however! word began to spread that mostof these gems were not antique! but rather were
contemporary pieces created by Italian craftsmen
following antique designs. The embarrassed collectors who had purchased the gems suddenly felt
themselves vulnerable! painfully aware of theirgeneral inability to safely tell the age of engraved gems.
In the walze of this scandal! the passion forcollecting antique engraved gems almost died. To
this day! interest in this specialized field remains
at levels far below those of the 18th and 19th centuries, despite the increased expertise in datingsuch pieces. Even the utilitarian value of seals wasdiminished by the invention of the gum-sealed
envelope and the development of the modern
postal system during the 1800s.
Although many important collectors left thefield and engraved seals lost the status of a major
art form) the rising middle class of the nineteenth
century adopted engraved gems for a different
purpose-in jewelry! particularly cameos. Several
factors are responsible for the renewed popularityof cameos. Large deposits of agate were discoveredin Brazil! which replaced the now-depleted German resources. This new agate was also well
suited for dyeing by newly discovered or rediscovered processesl thereby greatly increasing the
GEMS & GEMOLOGY

Winter 1983

Figure 10. This 19th century chalcedony cameo (85 m m wide x 59 m m high) is an excellent
example of the fine worlimanship that could be found particulurly early in this period. Like manyof he pieces created duringundufter the Renuissance, this Loo carries u clussical theme, "Death ofAdonis." Signed "Dreher," from a private collection. Photo 01983 Harold and Erica Van Pelt.

supply of raw material available for engraving. Although skilled artists could be found throughout
Europe! Idar-Oberstein became the center for thisnew production of brightly colored agate cameos.
The rediscovery of shell! which was ideal formass production because of the ease with which it
could be carved and the predictability of the layering! also increased the availability of cameos. Italian artisans were already slzilled at carving the
local coral and lava! and their tools and techniques
worked equally well on shell. Italy then as now
became the center for carving cameos out of shell.
The fact that England's Queen Victoria was a great
patron of shell cameos assured a steady demand formany years.
But while many fine cameos were created (seefigure lo]! particularly during the earlier period ofVictoria's reign! the mass production stimulated
by increased demand eventually led to poor
workmanship. Less experienced craftsman wereEngraved Gems

often allowed to do most of the worlz on thesecameos! the skilled artisan only adding the finishing touches. By the end of the 19th century) muchof the interest in cameos had subsided as well.
THE CURRENT STATUS
OF ENGRAVED GEMS
Engraved seals) while still popular in many Eastern
nations! are little used in the modern Westernworld. However! interest in other forms of engraved gems has been generated by a growing poolof slzilled artisans! the introduction of moresophisticated techniques, and the extension of engraving to larger objects and more unusual matterials. Idar-Oberstein! in particular! has led theway both in providing the in-depth training required to master this difficult art form and in taking the art form beyond the classical styles to experiment with new designs (figure 11). In an attempt to revive the areals gem-cutting industry
GEMS & GEMOLOGY

Wintcr 1983

199

Figure 11. Richard Hahn,
one of the most importantcaxvers i n Idar-Oberstein today, represents [he m a n ysl<illed artisans who are currently expanding the scope of
gem engraving.

after World War 11, many of Idar-Oberstein's
carvers turned their attention to engraving large
surfaces such as bowls, chalices, and plaques.
While chalcedony remained the favored material
for most of these pieces and the traditional cameos, other forms of quartz, tourmaline, and the likehave been used as well to demonstrate the versatility of the engraver's art (figure 12).
Recently, a challenge to the position of handengraving has appeared- that of ultrasonic engraving. Using ultrasonic drills, technicians can mass
produce cameos and intaglios in hard stone such as
chalcedony at a much faster rate than by the traditional methods. Whereas a medium-size cameo
may talze up to a day to complete by hand, these
new techniques can shorten the time needed toless than one hour. This is accomplished by constructing a steel cameo in positive from a handcarved cameo. From this steel positive numerous
copper negatives are madej each copper negative
has the ability to make one hard stone cameo by
guiding the ultrasonic drills. The results are virtually identical to the original model (Manfred
Wild, personal communication).

sideration. Fine detailing and variation in surface
finishes, such as a matte texture for clothing and aglossy finish for skin, create an illusion of depththat is almost three-dimensional. The piece
Figure 12. Tourmaline is one of [he newer materials used for gem engraving. This scene was engraved on the blue cap of ( I ~ozzrmalinecrys~alfrom the Qzzeen Iflinein California ( n o ~thena~zze
ral crys~aledge), Cameo (7 c m x 7 cm) courLesyof Gerhard Becker; photo 01980 Harold andErica Van Pelt.

EVALUATING ENGRAVED STONES
Evaluating gem engraving is very much Iilze evaluating any art form. Foremost in criteria is theoverall design. The observer should judge whether
the subjects shown are in proportion to one another and to the small field of the gem. The slzillful
depictioi~of depth and dimension is another conEngraved Gems

GEMS & GEMOLOGY

Winter 1983

should also be free of accidental tool marks, which
detract from the central theme or figure (Sinlzanlzas, 1968).
While most intaglios are constructed fromevenly colored stones, cameos are usually madefrom layered materials. The cameo artist painstalzingly selects chalcedony with good contrast between layers. This task is not an easy one, andtakes up much of the time of the engraver. Cassis
shell provides no such selection problem, as it isconsistently banded with strongly contrastinglayers. Whatever substance is used, the morelayers incorporated into the design, the more
complex the piece is and thus the more desirable i t
becomes. It is also axiomatic that the harder materials are more difficult to carve, and so are more
expensive to produce. Because of this, engraved
beryl or corundum is highly prized.
Today's collector of engraved gems faces formidable, but not unsurmountable, challenges. A
cultivated eye is developed from a study of theliterature relating to gem engraving and from amore than passive contact with actual pieces. The
first requirement, that of reading about the subject, is not'an easy one. As interest in this field goesin cycles, so does the volume of literature. The
most complete studies of engraved gems weremade in the 19th and early 20th centuries. Unfortunately, most of these suffer from much misinformation, are written in German or French, andare now out of print. Fortunately, more contemporary writers/scholars such as Boardman, Vollenweider, and Richter have made excellent, if
sometime esoteric, studies in English.
The most satisfying education, however,comes from actual observation. There are several
excellent museum collections in the United Statesand Europe, including the Boston Museum of Fine
Arts, the Metropolitan Museum of Art (in NewYork), the J. Paul Getty Museum (Malibu, California), the Oriental Institute (Philadelphia), theBurton Y. Berry Collection at the Indiana University Museum, the British Museum (London), andthe Louvre and Bibliotheque Nationale (Paris).Excellent examples of more modern pieces can befound in the Deutsches Edelsteinmuseum in
Idar-Oberstein, Germany. Dealers who specialize
in estate jewelry also often have cameos and intaglios of all periods.
CONCLUSION
The engraving of gems for use as seals, or as objectsof adornment, is one of the oldest of man's art
Engraved Gems

forms. Because of the hardness of most of the materials used, many engraved gems have endured
through thousands of years of recorded history,
and survived as glimpses of civilizations of which
few other tangible vestiges remain. Their lasting
charm has kept interest in engraved gems alive
through cultures down to our own.

REFERENCES
Anderson F.J. (1981)Riches of the Earth. W. H . Smith Publishing, New York.
Ball S.H. 11950)A Ronian Book on Precio~isStones. Gemological Institute of America, Los Angeles, CA.
Boardman J. (1968a)Archaic Creek G e m s . Northwestern University Press, Evanston, 1L.
Boardman J., Vollenweider M.L. (1978) Catalogue o f the Engraved G e m s and Finger Rings I. Greek and Etruscan.
Clarendon Press, Oxford, England.
Hinks P. (1975)Nineteenth Century Jewellery. Faberand Faber,
London, England.
King C.W. (1860) Antique G e m s , Their Origin, Uses, andValue. John Murray, London, England.
King C.W. (1885) Handbook of Engraved Gems, 2nd ed. George
Ball and Sons, London, England.
Morassi A. (1964)ArtTreasures o f the Medici. Oldbourne Press,
London, England.
Renton E. (1896) Intaglio Engraving. George Ball and Sons,
London, England.
Richter G.M.A. (1968) Engraved G e m s o f the Greeks and theEtruscans. Phaidon Press, Longon, England.
Sinkankas J. (1968) Van Nostrand's Standard Catalogue o f
Gems. Van Nostrand Reinhold Co., New York.
Sutherland B.B. (1965) T h e Romance o f Seals and Engraved
Gems. Macmillan Publishing Co., New York.
Wiseman D.J. (about 1956) Cylinder Seals o f Western Asia.
Batchworth Press, London, England.
SOME ADDITIONAL READING
Armstrong N . (1976)Victorian Jewelry. Macmillan PublishingCo., lnc., New York.
Becker V. (1980) Antique and T w e n t i e t h Century Jewellery.
NAG Press, London, England.
Boardman J. (1968b)Engravec/ G e m s . T h e Ionides Collection,
Northwestern University Press, Evanston, IL.
Boardman J. (1975)Intaglios and Rings. Thames and Hudson,
London, England.
British Museum (1976) Jewellery Through 700 Years. British
Museum Publications Ltd., London, England.
Frazier S. (1978-1981) The gem cutting industry of IdarOberstein. United Lapidary Wholesalers S h o w N e w s , Vol.
2, No. 2 through Vol. 5, No. 2.
Frazier S. (1981)The gem cutting industry of Idar-Oberstein.
feweler/Lapidary Business, Vol. 5, Nos. 3 and 4.
King C.W. (1872)Antique G e m s and Rings, Vol. I and 11. Belland Daldy, London, England.
Long F.W. (1982)Lapidary Carvings, Design and Technique.
Van Nostrand Reinhold Co., New York.
Middleton J.H. (1891)T h e Engraved G e m s o f Classical Times.
Cambridge University Press, Cambridge, England.
Osborn D. (1912)Engraved G e m s . Henry Holt and Co., NewYork.
Ward A,, Cherry J., Gere C., Cartlidge B. (1981)Rings Throughthe Ages. Rizzoli, New York.

GEMS & GEMOLOGY

Winter 1983

201

GEM m D W I T E GARNETS
By Carol M. Stockton and D. Vincent Manson

Andradiie, the rares t o f the five wellk n o w n gem garnet species, i s examined
and characterized with respect t o refractiveindex, specificgravity, absorption spectrum, color, and chemical composition.
These properties are measured and specifically t a b ~ ~ l a t efor21dgem undrudites (20green and one yellow), From the narrow
ranges of refractive index (1.880-1.883),
specificgravity (3.80-3.881, and chemicalcomposition (less than 3% of components
other than andradite i n any o f the specimens examined) that were observed, i t isapparent that t h e g e m - q ~ ~ a l iundraditesty
are chemically distinct from other types o f
gem garnets and that these stones are easy
to distinguish b y means of color coupledwith refractive index.

ABOUT THE AUTHORS
Ms. Stockton is senior research gemologist and Dr.
Manson is director of research at the Gemologicallnstitute of America* Santa Monica, CA,
Acknowledgments: We would like to thank the following individuals for their contributions to this article: Michael Allbritton for the loan of a demantoid
from his collection, John Koivula for the photographin figure 2, Michael Havstad for the remaining
photos, and Lisa Joko for the line drawings. Our
appreciation also goes to the California Institute ofTechnology for the use of [heir MAC microprobe
and to Arthur Chodos and Randy Heuser for theirassistance with the instrumentation.
0 1984 Gemological Institute of America

202

G e m Andradite Garnets

As part of our continuing study of gem garnets) the
species andradite should present few difficulties incharacterization and identification. Three varieties havebeen recognized by gemologists: melanitel topazolitel anddemantoid. Melanitel which is blaclzl will not be discussed
here because it is opaque and has historicallyl to ourlznowledgel been used as a gem only for mourning jewelry.
Topazolitel a term that has been challenged as being too
similar to that of the gem species topazl is a greenish
yellow to yellow-brown andradite that only occasionallyoccurs in crystals large enough to be faceted. Demantoid!
the yellowish green to green variety (figure 1))is the mostimportant of the three for the jeweler-gemologist and is theprincipal focus of the study reported here.
Pure andradite (Ca3Fe2Si3012)
has a refractive index of
1.886 (McConnelll 19641 and a specific gravity of 3.859( S l z i ~ e 1956).
r ~ Gemological references cite ranges as narrow as 1.888 to 1.889 for refractive index and 3.82 to 3.85
for specific gravity (Webster)1975)and as broad as 1.855 to
1.895 and 3.81 to 3.87) respectively (Liddicoat) 1981J.
Demantoid has been observed to exhibit a visible light
spectrum that has a very strong absorption band centeredaround 443 nml which may appear as a cutoff) andl in thecase of finer green stones) two bands around 622 nm and
640 n m as well as a pair of bands between 693 and 701 nm(Anderson and Payne! 1955).Liddicoat (1981)and Webster(1975) both support these observations. Anderson and
Payne attributed the 443 nm band to Fe3+ and the remaining four bands to C9+.
Two distinct characteristics of demantoid are usuallyused as visual indicators in identification. One is the verystrong dispersion (0.057j1which can be observed in almost
any cut stone. The other is the frequent presence of "horsetail1' inclusions (figure 2) of byssolite fibers (Gubelin)1974). These inclusions are so unique and characteristic

GEMS & GEIMOLOGY

Winter 1983

that demantoid is frequently cut so as to position
them directly beneath the table of a stone where
they are unmistalzably visible.
DATA COLLECTION
Because of the rarity of gem-quality andradites! wewere able to compile a collection of only 21 samples: one brownish yellow stone and 20 green ones!
of which 10 were from a single parcel. We attempted to add variety by borrowing stones! but
only one specimen (#L-1)among those available tous was of a type not already represented by stones
from GIA's reference collection. Moreover! reliable information on the origins of gems is exceedingly scarce (as compared, for instance! to collectible mineral specimens);among the stones studied
here! only the locality of the brownish yellow
specimen from California is Iznown for certain.
Each stone was measured for refractive index,
specific gravity) absorption spectruml colorl andchemical composition. The instruments andtechniques employed for data collection were thesame as those used in the previous portions of thegarnet study and described in detail in our initial
paper in this series (Manson and Stockton) 1981).
However, because the microprobe system we usefor quantitative chemical analyses reports all iron
as Fe2+ while the iron in andradites is present
principally as Fe3+! mathematical conversion wasnecessary to correct the appropriate percentages.
Any error in the determination of Fez+ by the
microprobe is compounded by this calculation, so
we performed chemical analyses four times foreach stone and averaged the results in an effort toincrease the accuracy of the original figures. The
data are summarized in table 1.
DISCUSSION OF DATA
Physical and Optical Properties. The ranges of refractive index and specific gravity that we obtainedfor our 21 andradites are quite narrow in coinparison to other types of garnets: 1.880-1.883 and3.80-3.881 respectively. The refractive indicesthat we observed fall within the range cited by
Liddicoat (1981)and below that of Webster (1975)!
as discussed above. The specific gravities for our
specimens define a somewhat broader range thanthose proposed by the aforementioned sources.
The often highly included nature of even gemquality andradite would be sufficient to accountfor considerable variability in this property.

GEMS & GEMOLOGY

Winter 1983

Figure 1 . Andradite garnet, gem variety
demantoid (GZA no. L-1).

Che~nistry.It is evident from table 1 that there isvery little variability in chemical composition
among the andradites that we examined! especially when compared to other types of garnets.
Moreover! this laclz of deviation is reflected in thevery narrow ranges observed for refractive indicesand specific gravities. Greater compositional variation does occur in non-gem-quality andradites(Deer et al., 1963) to the extent that they appear tocontinuously grade into grossular. However! to ourlznowledge no gem-quality garnets with these intermediate compositions have been observed.
An examination of the totals in table 1 foroxide and end-member compositions reveals that
our method of calculating garnet end members
does not account for the oxides in andradites aswell as it has for other types of garnets (Manson
and Stoclztonl 1981). Comparison of figure 3 with
Figure 2, "Horsetail"-type inclusion in ademon toid andradite. Magnified 50 X.

G e m Andradite Garnets

203

the histogram in our first article on garnets (figure
2, op. cit.)will clearly confirm this difference. The
deficiency appears to be in cations that occupy theoctahedral site (represented by Y in the garnet formula X3Y2Z3012)leaving an excess of cations forthe dodecahedra1 (XJ and tetrahedral (ZJsites, especially calcium and silicon. This may be due tothe possibility that andradite does not behave according to the ideal garnet formula employed byour end-member calculation scheme. Anotherlikely explanation, especially evident in the largescale conversion of FeO to Fe203 necessary for
andradites, involves the presence of different oxidation states that cannot be distinguished with themicroprobe (Huggins et al., 1977; Burns, 1981).In
addition, there may be minor water contentfairly common in andradites (Deer et al., 1963)that also cannot be detected with the microprobe.

1

YOACCOUNTED FOR BY END MEMBERS

Figure 3. Histogram illustrating the percentagesof oxides in the 21 andradites that are accounted
for b y end members.

It is interesting to note the low accountability that
occurred with the one brownish yellow stone(#I16481 that we examined.

TABLE 1. Physical, optical, and chemical data for 21 andradites from various I o ~ a l i t i e s . ~Italy

Physical, optical, andchemical properties(2491)

Refractive index
Specific gravity
ColorMasler coordinates
CIE xly coordinates
GIA color terminologyb
Oxide compositionc
Si02(29526)( I 31 32)(6672C)(6672D)(13234)(13254)(6672A)(13163A)

1.881
3.85
A-I 8/34/01
0.446/0.482
YG 314
35.33
0.10
30.56
<0.05
0.09
0.24
33.66
<0.05

A1203
Fe203dcr203
Ti203d
M!30
CaO
MnO
Total
End-member composilion~
Schorlomite
Andradite
Uvarovite

100.08Total
Spectral absorptionb d n d ~(nm)

97.76

0.36
97.24
<O. 16

475
565
621
738

aThe GIA catalogue number for each stone is indicated in parentheses,b ~ o l o terminolopyrrefers to "hue tone/saturation." The symbols are interpreted as follows:
Hue: s = slightly Tone: 2 = very light
Saturation: 2 = slightly grayish hue
o = orangy
3 = light
3 = very slightly grayish hue
4 = medium light
4 = huey = yellowish
Y = yellow
G = green
-

204

-

Gem Andradite Garnets- -----GEMS & GEMOLOGY

Winter 1983

Another point of interest is that some of thestones apparently are not homogeneous in compositionl especially with regard to chromium. The
Cr203content of one stone was determined in four
separate analyses to be 0.18) 0.26) 0.13) and 0.05
weight percent. For comparisonl the four analysesof another stone revealed 0.0810.06) 0.07! and 0.06
weight percentages of Cr203.

Color. The range of colors of gem andradite is fairly
narrow and) with the exception of the rare and very
desirable vivid green) is well represented by thestones we examined (figure 4). Consequentlyl the
distribution of the color coordinates for thesestones in the CIE color graph occupies a very small
region (figure 5) in comparison to the broad color
variability seen in most ty-pes of garnets. We did
not observe color zoning in any of our stones) evenin those with chemical analyses that suggested
nonhomogeneous distribution of potentially colorinfluencing elements. Nor could we correlate thesmall amounts of Cr203measured in these stones
with variations in hue) since the quantities inmany of the stones approached the limits of detection of the microprobe. In most cases) therefore)
our figures for chromium incorporate a relatively
high level of uncertainty.
Manganese and titanium have also been associated with color origin in andradites. The exact
role of the latter has been the subject of considerable debate among mineralogists (Howie andWoolleyl 1968; Moore and White) l97zj Manningand Harris, l97Oj Huggins et al.) 1977). The lowlevels of titanium present in the stones we analyzed could not be measured with sufficient accuracy to contribute toward clarifying the signifi---(13163C)

--

USSR

, ,
(13163B)--(13163D)(13163E)(13163F)(13163G)(13163H)(131631)(13163J)(13103)--

San Benilo
Co., Calif.

Unknown(1 1648)

(L-I)

1.880
, 1,880
1 881
1.881
1.880
1.882
1.882
1.881
I.883
1.880
1.881
1.881
3.87
3.84
3.88
3.84
3.83
3.86
3.87
3.83
3.83
3.81
3.80
3.87
A-20/50/03 A-1 7/50/02 A-18/52/04 A-I 9/58/04 A-20/57/05 A-1 7/52/02 A-20/57/03 A-21/52/04 A-24/65\05 A-28/64/05 B-83/96/01 A- 18/56/02
0,401/0.487 0.392/0.5 I 7 0.381/0.482 0,37810 490 0.377l0.473 0,385/0.517 0,391/0.495 0.392/0.469 0,388/0.478 0,407/0.465 0,528l0.444 0,388/0.520
YG3/3
yG3/3
yG3/2
syG3/3syG3/2
yG3/4
yG3/3
YG3/2
yG2/2
YG2/2
soy314yG3/4'For a discussion of accuracy, see Appendix. Oxide figures are given as weigh1 percentages.
d ~ lFeOland Ti02 were converted lo Fe203 and Ti203 in accordance with the requirements of stoichiomefry
eMn3V2Si3072,knorringile, spessarline, grossular, and almandine were also considered by our end-member
calculalion program, but were all elirninaled in the process due lo the absence of the necessary oxides,

Gem Andradite Garnets

GEMS & GEMOLOGY

Winter 1983

205

Figure 4, A selection ofstones from the collection of
andradite garnets used inthis study which illustrates
the ranges of colors of thestones examined. (From left
to right, GIA nos. 11648,
2491, L-1,13254, and2952B.)

cance of titanium in andradites) but the possible
effect of this element must not be ruled out. The
presence of manganese in andradites has been documented in association with dark yellowish or
reddish hues (Vermaas)1952).Minor MnO content
was detected in the one yellow-brown andraditethat we analyzed) but this information is not sufficient to support any conclusions about the effects of manganese on the color of andradites,
Finallyl the effects of different valence statesand site occupancies of iron must be considered asa possible cause of color variation. There is evidence in the literature (Huggins et al.) 1977;
Schwartz et al.! 1980; Burnsl 1981) that iron) especially in the presence of titanium as in garnets of
the andradi te-schorlomite series) can be present inboth divalent and trivalent states and can occupy
sites other than those normally associated withthose states. While these studies do not yet correlate such a distribution of iron with specific color
effectsl they do identify that absorption of visible
light and associated variations in color result fromsuch relationships /Marfuninl l97gj Burns, 198 1).
Spectrum. With the spectrophotometerl three absorption bands could usually be discerned in thevisible light range: at approximately 446 nml 573
nml and 620 nm (figure 6). The latter two bands
may overlap considerably and at times appear as asingle broad absorptionl especially in the yellowish green to yellow-brown stones. In this form,
they are centered around 600 nm and are referredFigure 5. Left, the CIE chromaticity diagrum with an indication of the region (shaded area)
reproduced at right; x indicates the coordinates for colorless or neutral gray. Right, theyellow-green to yellow region of he CIE cl~romaticitydiagram with positions for the 21
andradites plotted according to their x-y color coordinates.

Gem Andradite Garnets

GEMS & GEMOLOGY

Winter 1983

to in the mineralogical literature as associatedwith the presence of Fe3+ in the octahedral site
(Slack and Chrenko, 1971; Moore and White,1972). These references assign the same significance to the 446 nm band. Only one source (Amthauer, 1976) refers to a single band near 621 nm
and attributes it to Cr3+, but no source has citedthe 573 band separately. These bands may also
reflect the presence of Cr3+,which appears in grossulars as bands around 427 nm and 61 1 nm (Amthauer, 1976),but the overlap of such Cr3+bands
with those of Fe3+ in andradite would make i tdifficult to separate their respective influences oncolor. In addition, we observed a well-defined bandin the near-infrared region, around 740 nm, in overhalf of the andradites. As yet, we have found noreference to this band in either the mineralogicalor gemological literature, nor any correlation withchemical composition in the stones in which i t
was observed.
With the hand spectroscope, the absorption
spectrum reveals a strong band at 430 to 445 nm,
which at time appears as a cutoff at 445 nm, and avague, broad band centered at approximately 590
nm (figure 7). The latter, it should be noted, is not
mentioned in the gemological sources we cited in
the introduction to this article. We were unable toconfirm the paired bands associated with richgreen color and/or Cr3+ mentioned by these same
sources (Anderson and Payne, 1953- 1957; see also
those cited in the introduction to this article),
since they were not present in the spectra of any of
the stones we examined, probably because none of
our specimens were of the finest green color associated with demantoids. We would welcome theopportunity to examine such material if it weremade available to us.

Figure 6. Representative spectral curve of ademantoid (no. 131633) as observed with thespectrophotometer. Principal absorption andtransmission features are labeled w i t h their specific wavile&ths. All or most of these features
were observed i n all the demantoids examined.

CONCLUSIONSAs in our previous studies on garnets, the definition of varieties according to characteristic spectra
and corresponding color-causing elements has
proved to be complex. We were able to detect nocorrelation between color, spectral absorption
bands, and the amount of Cr203 present in thestones we examined. However, we have no reason
to question the existence of absorption bands
associated with high Cr203 content in more intensely green demantoids. The influences of titanium and manganese on the variability of color
among gem andradites are still very questionable.
While Fe^ in the octahedral site is responsible forthe yellow-green color of most gem andradites,
iron in other valence states and in other sites in thegarnet structure may also contribute to variation.
The high proportion of the andradite component in gem andradites provides ease in clearly
defining the gem species associated with this end
member of the garnet group. It is characterized byvery little variability in chemical composition andin optical and physical properties in comparison
with other types of garnets. Members of the gem
andradite species can be easily distinguished bymeans of their high refractive index (1.880- 1.883)
in conjunction with color. No other type of gem
garnet that has a refractive index over 1.80 occurs
in green to yellow-brown hues. The precise definition of the gem varieties of andradite will be discussed in our concluding article on the gem garnets as a whole.

4i0nrn

830 nrn

Figure 7. The same absorption spectrum illustrated in figure 6 as i t is seen with the hand spectroscope. The absorption features in the blue region often appear as complete absorption below
approximately 440 n m to 445 nm.

Gem Andradite Garnets

GEMS & GEMOLOGY

Winter 1983

207

APPENDIX
The accuracy of our chemical data is affected principallyby the amount of chemical inhomogeneity in our samples and by the variability and bias inherent in the techniques employed in chemical analysis. Aside from the
problem of inhomogeneity, the accuracy of our microprobe data can be assessed through an examination of
the variation among selected analyses of a well-known
standard material, the McGetchin garnet (McGetchin,
19681, which we analyze each time we place a set of
specimens in the instrument. Table 2 provides ranges,
averages, and standard deviations for 25 microprobe
analyses of the McGetchin garnet collected over a twoyear period in conjunction with the analyses of thespecimens described in this article.

TABLE 2. Ranges, averages, and standard deviations for
25 microprobe analyses of the McGetchin garnet over a
two-year period.
Oxide
SiO,
Ti02
A1203

crz03
"2O3
Mgo
CaO
MnO

FeO

Range
of wt %

Averageof vdt %Standard
deviation (%)

40.45-42.30
0.12- 0.20
21.62-22.94
1.32- 1.44
0- 0.08
19.60-20.42
4.47- 4.69
0.29- 0.50
8.99- 9.55

REFERENCES
Amthauer G. (1976)Kristallchernie und Farbe chromhaltiger
Granate. Neues fahrbuch fur Mineralogie Abhandlungen,Vol. 126, No. 2, pp. 158-186.
Anderson B.W., Payne C.J. (1953-1957) The spectroscope andits applications to gemmology. The Gemmologist, Vol. 22,
No. 266 through Vol. 26, No. 306.
Anderson B.W., Payne C.J. (1955)T h e spectroscope and its
applications to gemmology, part 17: Absorption spectrumof demantoid garnet. The Gemmologist, Vol. 24, No. 282,
pp. 5-8.
Burns R.G. (1981)lntervalence transitions in mixed-valenceminerals of iron and titanium.Annua1 Review of Earthand Planetary Science, Vol. 9, pp. 345-383.
Deer W.A., Howie R.A., Zussman J. (1963)Rock-Forming
Minerals, Vol. 1, Ortho- a n d Ring Silicates. Longman
Group, London, pp. 77- 112.
Gubelin E. (1974)InternalWorld of Gemstones. ABC Druckerei & Verlags AG, Zurich.
Howie R.A., Woolley A.R. (1968)The role of titanium and theeffectof TiO2 on the cell-size, refractive index, and specificgravity in the andradite-melanite-schorlomiteseries. Mineralogical Magazine, Vol. 36, pp. 775 -790.
Huggins F.E., Virgo D., Huckenholz H.G. (1977)Titaniumcontaining silicate garnets. 11. T h e crystal chemistry of
melanites and schorlomites. American Mineralosist,- Vol.
62, pp. 646-665.
Liddicoat R.T. Tr. 119811Handbook of Gem Identification.
~ e r n o l o ~ i c a l ~ n s t i tof
u America,te~ a n t aMonica, CA.
Manning P.G., Harris D.C. (1970)Optical-absorption and electronmicroprobe studies of some high-Ti andradites. Ca-

208

Gem Andradite Garnets

nadian Mineralogist, Vol. 10, Part 2, pp. 260-271.
Manson D.V., Stockton C.M. (1981) Gem garnets in the redto-violet color range. Gems &> Gemology, Vol. 17, No. 4,
pp. 191-204.
Marfunin A S . (1979)Physics of Minerals and Inorganic Materials. Springer-Verlag, New York.
McConnell D. (19641Refringence of garnets and hydrogarnets.
Canadian Mineralogist, Vol. 8, pp. 11- 12.
McGetchin T.R. (1968) T h e Moses rock dyke: geology,
petrology and mode of emplacement of a kimberlitebearing brecchia dyke, San Juan County, Utah. Ph.D. thesis, California Institute of Technology, p. 189.
Moore R.K., White W.B. (19721 Electronic spectra of transition
metal ions in silicate garnets. Canadian Mineralogist, Vol.
11, Part4, pp. 791-811.
Schwartz K.B., Nolet D.A., Bums R.G. (1980)Mossbauer spectroscopy and crystal chemistry of natural Fe-Ti garnets.
American Mineralogist, Vol. 65, pp. 142- 153.
Skinner B.J. (1956)Physical properties of end-members of thegarnet group. American Mineralogist, Vol. 71, pp.
428-436.
Slack G.A., Chrenko R.M. (1971)Optical absorption of natural
garnets from 1000 to 30,000 wavcnumbers./o~irnalof theo p t i c a l Society of America, Vol. 61, No. 10, pp.
1325-1329.
Vermaas R.H.S. (1952) Manganese-iron garnet from Otjosondu, South-West Africa. Mineralogical Magazine, Vol.
29, pp. 946-951.
Webster R. (1975)Gems,3rd ed. Butterworths, London.

GEMS & GEMOLOGY

Winter 1983

THE RUBIES OF BURMA:
A REVIEW OF THE MOGOKSTONE TRACT
By Peter C. Keller

For centuries, the Mogok Stone Tract of
Burma has provided the world with its finest rubies. The mining district is situatedabout 700 k m north of the capital city ofRangoon, with the rubies found principallyi n alluvial deposits weathering out of acrystalline limestone or marble. This article
reviews the history of this famous locality,
the geology-of the area, and the mining
methods that have predominated. Also
covered is the gemology of these stones, including those inclusions that are characteristic of Burmese origin, and a discussion of
famous rubies from Mogok.

ABOUT THE AUTHOR
Dr. Kelleris director of education at the Gemological
Institute of America, Santa Monica, California.
Acknowledgments: The author wishes to thank Ed
Swoboda, Harold and Erica Van Pelt, and Alan
Caplan for the photos that they so graciously
loaned. John Koivula was particularly helpful inproviding information on inclusions in Burma rubies
and the photomicrographs in figures 7, 8, and 9.
Ruth Patchick did a superb job of typing the manuscript from very rough drafts.
07984 Gemological Institute of America

The Rubies of BurmaI

t is impossible to consider the "classic" or historicallymost important gem deposits of the world without
including the Mogok Stone Tract in Upper Burma. Mogolz
has been associated with the world's finest rubies for overfour centuries, but not until the British assumed control of
Burma in 1886 was Mogok's potential for producing beautiful, deep crimson ("pigeon's blood") rubies truly realized(figure 1).Although Mogolz is known particularly for thesefine rubies, quantities of fine sapphires, spinels, andperidot are also found in the Mogolz Stone Tract. Sapphires
are most abundant in the nearby Kathe, Kyatpyin, andGwebin deposits; peridot is limited to the area of
Bernardmyo some 10 km NNW of the village of Mogok.
Also found in gem quality in the Mogolz area are apatite,
scapolite, moonstone, zircon, garnet, iolite, and amethyst.
Historical records indicate that the Mogolz Stone Tract
has been worked since at least 1597 A.D., when the King of
Burma secured the mines from the local Shan [Mongoloid)
ruler. After the British annexation of Upper Burma in 1886,
the mines were leased to a British firm, which organized
Burma Ruby Mines, Ltd. Although the British firm used
modern methods to work the mines, it found that theirprofitability was sporadic at best. Burma Ruby Mines
worked the area until the early 1930s, when Mogolz reverted back to native mining and the methods used for
hundreds of years before the arrival of the British.
Today, little information comes out of Burma regarding the Mogolz Stone Tract. Since 1962, when the communist regime took power and subsequently nationalized
all industry including gem mining, no foreigner has been
allowed to visit Mogolz. During this period, supplies ofrubies from Burma have diminished drastically. Althoughsome stones are sold at annual auctions in Rangoon,
the few quality stones that emerge are smuggled out
through Thailand.
The purpose of this article is to describe what is known

GEMS & GEMOLOGY

Winter 1983

209

of this "premier" ruby deposit. Because it is impossible for foreigners to visit Mogolz, the research
for this article consists of a thorough review of theliterature as well as interviews with people who
had visited Mogolz prior to 1962. The photos,
which come from some of these same gem dealers,
are particularly rare. The literature is rich in information on Mogolz, usually based on a visit to
the area by some Western gem dealer. The firstsuch report was that of Pierre dlAmato (18331,who
described the local mining methods in the Mogolz
area. Since then many articles have been written,
principally on the mining activities (Wynne, 1897;
Morgan, 1904; Gordon, 1888; Scott, 1936).However, since the 1965 article by Gubelin, who also
produced a superb two-hour documentary film on
the area, nothing of importance has been contributed to the modern literature.

LOCATION AND ACCESSThe Mogolz Stone Tract is located in the Kathe
district of Upper Burma between latitudes 22O
50'45" N to 2 3 O 5'15" N and longitudes 9G0 19' E to
9G0 35' El or approximately 700 km north of the
Burmese capital of Rangoon. Mogok (figure 2) isabout 150 lzm NE of Mandalay, and is located at anelevation of about 1,200 m (4,000 feet). It is the
major population center in the area, with 6,000
inhabitants reported in 1960 (Meen, 1962). The
tract is about 1,040 square kilometers in extent
and includes the townships of Thabeiklzyin and
Mogolz.
The general area of the tract is very mountainous, forming the western borders of the Shan Plateau. Most of the mining takes place in the alluvia
of floors and flanks of the Mogok, Kyatpyin, Kathe,and Luda valleys. Mogok Valley is the most important, consisting of a narrow alluvial plain, 5 lzm
long running NE-SW, and about 1 lzm wide.
All reports of travel to Mogolz, when it was
permitted, indicate that access to the mining area
was very difficult. According to Ehrmann ( 19571,
there were two principal travel alternatives. The
first started with three days by train from Rangoon
to Mandalay, followed by two days of boat travelup the Irrawaddy River to Thabeiklzyin, where one
could hire a car for the final 95 tortuous lzilometers. The second, and far easier, means was a fourto six-hour flight from Rangoon to Momeik via
Union of Burma Airways, and then about 40 lzm byjeep from Momeilz to Mogolz.
Because the current Burmese government

210

The Rubies of Burmalimits foreign visitors to a 24-hour visa, any travel
into the interior is virtually impossible. In addition, the Mogolz area is under military control andvisits by foreigners are forbidden (Nordland, 1982).

HISTORY A N D PRODUCTION
According to Webster (19751, the earliest historical
record of Mogolz shows that the mines were takenover by the King of Burma in 1597 from the local
ruling Shan, in exchange for the town of Mong Mit(Momeik)some 40 lzm away. The descendants of
the king worked the mines intermittently. In
1780, King Bodawgyi operated the mines using
slave labor. Shortly thereafter, the king placed control of the Mogok mines in the hands of governors(So's) who allowed mining on payment of a tax.
Valuable stones remained the property of the king,however, with no compensation to the miner. This
period was one of great oppression, and many
miners left the region. The area never really recovered, and by the 1870s conditions were so intolerable that King Thebaw began negotiatingwith outside companies to work the deposits. He
eventually leased mining rights to the Burmah (sic]And Bombay Trading Company, but arbitrarily canceled their lease on the ruby mines in 1882
(Mineral Resources, 1886).This action, along withcertain provocations to the British-controlledlumber industry, led the British to invade Upper
Burma in 1886 with an army of 30,000 men (Mineral Resources, 1886).The British annexed Upper
Burma to the colony of India that same year. In
October 1887, the Upper Burma Ruby Regulations
were promulgated, creating the so-called "stone
tracts." In November of that year, the Mogolz
Stone Tract was established (Chhibber, 1934a andb]. In 1889, the British government, through theSecretary of State for India, awarded control of the
Mogolz mines to Edwin Streeter, the eminent Bond
Street (London) jeweler, who organized Burma
Ruby Mines, Ltd. The initial 1889 lease of themining rights to the 10 x 20 mile (15 x 30 km) tract
was for a seven-year period at an annual rent ofÂ£26,66 plus 16.66% of the net profits (Adams,
1926).
When Burma Ruby Mines, Ltd., moved into
Mogolz they faced severe difficulties, not the leastof which was that they found the richest deposits
to be under the village of Mogolz itself. Before mining could begin, they had to move the entire village
to its present location. In the years that followed,
they also had to build roads, bridges, buildings, five

GEMS & GEMOLOGY

Winter 1983

Figure 1. The eight unusually large rubies in this exquisite necklace well illustrate the"pigeon's blood" color so distinctive of fine Burmesestones. The rubies total 66.51 ct, and aresurrounded by 96.99 ct of diamonds. Photo b y Herbert Giles; courtesy of Harry Winston, Inc.
(Editor's note added post-printing: We regret that given the limitations of the four-color
process w e could not accurately capture the deep color of the original stones.)
The Rubies of Burma

GEMS & GEMOLOGY

Winter 1983

211

washing mills, and a 400-1zw hydroelectric plant.
In addition, the company was plagued by the ageold problem of miners "highgrading" and smuggling a large percentage of the gem production(Brown, 1933). The Indian government protected
the local miners, stating that Burma Ruby Mines
could not disturb established native miners intheir work, nor remove them except by purchase of
their claims. Otherwise, the British company helda monopoly on the mining rights of the Mogolz
Stone Tract (Adams, 1926; Calhoun, 1929).
In 1896, the original seven-year lease was renewed and extended for 14 years with a fixed rental
fee of Â£13,33plus 30% of the net profit per year.
The mining of rubies in Mogolz was at an all-timehigh. Five large washing mills processed
thousands of tons of earth each day. The area eventually became so prosperous that more mills wereerected 12 km from Mogok, near Kyatpyin. All
mining was open pit, using large hydraulic monitors, or "cannons," under high pressure to wash
the gem gravels through a series of sluice-boxes(Webster, 1975).
The area prospered under the control of Burma
Ruby Mines until 1908, when large numbers ofsynthetic rubies entered the world gem market.
This caused immediate panic among ruby buyers
worldwide, and sales of rubies declined dramatically. Although the Mogolz operations continued
all through World War I, in 1925 Burma Ruby
Mines went into voluntary liquidation (Brown,1933).The company had six years remaining on its
lease, however, and struggled on until 1931, wheni t surrendered the lease to the government(Halford-Watkins, 1932).
Keely (1982))one of the managers of the mine,
gives some additional insight into the decline ofmodem mining in the Mogok area. He points outthat exceptionally heavy rainfall in 1929 caused
severe flooding, which destroyed all of the electric
pumps as well as the drainage tunnels used to keep
the mines from being inundated. The large lake
formed by the flooding still remains today (again,
see figure 2).Several attempts were made to repair
the flood damage, but with no success. Furthermore, as the modern techniques were no longer
considered economic, the native miners and theircenturies-old mining methods took over Mogolz
once again. All lease restrictions with respect toapplications for licenses were removed, and thegovernment simply collected 10 rupees per monthfrom each miner to cover the cost of a license that212

The Rubies of Burma

the miner "was to wear on the seat of his pants"(Halford-Watlzins, 1932). Native mining continued actively except during the period May 1942 to
March 1945, when the Japanese occupied Burmaand the Mogolz tract became part of the battleground of the 14th U.S. Army and the Japanese.
After World War 11, native mining prospered until
the nationalization of the mines by the communist regime in 1963.
When the Burmese government nationalized
all industries in 1963, it forbade all private businesses, including gem mining and selling. Today,
the diminished gem mining is monitored by thearmy, and gems can be sold legally only at theannual auction held in Rangoon by the Petrol andMineral Development Corporation [PMDC).
These auctions have not been highly successful
because of the generally poor quality of the stones
offered. The total sales figures from the annual
gem emporium, as published by the Minerals
Yearbook, gives some idea of modern production.
In 1969, the Fifth Annual Gem Emporium yielded$2,400,000. This figure rose dramatically in 1973
to $5,800,000, the last year for which statistics areavailable, but it is important to note that this sum
represents mostly income from sales of jade andpearls, with very few rubies having been offered.
Early production records are difficult to findand are generally incomplete. According to Iyer
(1953),in a table of production statistics for the
Burma Ruby Mines, Ltd., 1,300,000 ct of ruby wererecovered during the period 1924- 1939. As usualwith gem production statistics, it is impossible
to know how much additional material wasrecovered by highgraders and operators ofprivate claims.
According to Nordland (19821, the Mogok area
is off-limits to foreigners, and closed even to Burmese without special permission. A division of
Burmese troops now oversees the govemmentowned mines.
GEOLOGY
Several detailed accounts of the geology of the
Mogok Stone Tract have been published. The earliest is the large and comprehensive work of Brown
and Judd (1896), who conducted their study onbehalf of the Burma Ruby Mines, Ltd., and theSecretary of State for India. La Touche, perhaps
best known for his work on the Kashmir sapphiremines, included the Mogolz area in his Memoir of
the Northern Shan States (LaTouche, 1913).OtherGEMS & GEMOLOGY

Winter 1983

Figure 2. A view of the town of
Mogok from across theartificial lake that resulted
from the flooding of theextensive works of the
Burma Ruby Mines, Ltd.

early geologic studies include Bleeclz (19081, Fermor (1930,1931,1932,1934, and 1935),and Heron(1936 and 1937). Chhibber (1934a) includes a description of the gem gravels in his work on thegeology of Burma.
Systematic mapping of the Mogolz Stone Tracton a scale of 4 inches = 1 mile was started in 1929
and published by Brown (1933). Much more extensive mapping, however, was continued by Iyer
(1953).This work is by far the most complete on
the Mogok area, and resulted in a superb map of thedeposit (as adopted for figure 3).
As is the case with all tropical areas, the geologic mapping of Mogolz was particularly difficult.
Not only must the geologist contend with dense
vegetation and numerous wild animals, but hemust also study roclzs that are covered with a thickmantle of soil and products of deep chemical
weathering. In the Mogolz area, annual rainfall ismore than 360 cm (140 in.).
We do know that the geology of the Mogolz
area is very complex, consisting primarily ofhigh-grade metamorphic schists and gneisses;
granite intrusives, including gem-bearing pegmat i t e ~ peridot-bearing;
ultramafic rocks; and, mostimportantly, ruby- and spinel-bearing metamorphic marble.
The rubies of Mogok are weathered from themarble of the area, which is in contact or interbedded with a complex series of highly folded
gneissic rocks. Iyer (1953)identified 13 mappablerock units in the Mogok area. These, however, canbe, and often are, grouped into (1)intrusive granitic
rocks; (2) the Mogolz gneiss, which consists of

The Rubies of Burma

metamorphic schists and gneisses; (3) the Pleistocene and recent (Quaternary) alluvium; (4) ultramafic intrusives; and (5) marbles (again, see
figure 3).
The Mogok gneiss is the prevalent rock unit in
the region. It consists of many types of metamorphic rocks, including scapolite- and garnet-richbiotite gneisses, calc-granulites, quartzites,
garnet-sillimanite-rich gneisses, and hornblendeschists and gneisses. The Mogok gneiss makes up
the eastern two-thirds of the area mapped by Clegg
and Iyer (Iyer, 1953). The marbles, which are thehost rocks of the rubies and spinels, are intimatelyinterbedded with the Mogok gneiss. Roundedfragments of the Mogok gneiss are a major constituent of the gem gravels. Because of the heavy rainfall and tropical climate of the region, the Mogok
gneiss weathers very quickly to a reddish lateritic
soil, leaving only rounded boulder remnants.
The granitic intrusives in the Mogok area form
most of the western third of the Stone Tract. On
the detailed geologic map of Clegg and Iyer (Iyer,
19531, they consist of the Kabaing granite, anaugite and hornblende granite, a syenite, and a
tourmaline granite. Pegmatites containing topaz,
tourmaline, and aquamarine are also included inthis map unit. Many small exposures of granitic
rock have been included in the unclassified crystallines of the Mogolz gneiss.
Of the granitic intrusives mapped by Clegg andIyer, the Kabaing granite is by far the most important and one of the largest rock units i n the area. It
is found in workings throughout the Mogolz area,and much of the gravel encountered in the allu-

GEMS & GEMOLOGY

Winter 1983213

QUATERNARYALLUVIUM

MOGOKGNEISSINTRUSIVEGRANITESCRYSTALLINE-6vium is undoubtedly derived from this granite.
The Kabaing granite contains bands of marble andappears to be responsible for the contact metamorphism that formed the gem rubies and spinels of
the Mogok Stone Tract.
The Kabaing granite contains numerous
quartz and topaz-bearing pegmatites, with cassiterite noted in abundance in certain of these bodies.
Iyer (1953)states that two topaz crystals weighing
about 5 kg each were kept in the office of the
Burma Geologic Survey. Such gem minerals, alongwith large quartz crystals, were generally sold toChinese traders for carving.
Basic intrusives are very rare in the Mogok
area, and are limited to gabbros and hornblendepyroxene rocks, as well as to peridotites found as
minor intrusive dikes and sills principally in the
Bernardmyo area about 10 km north of Mogok.
These rocks are of minor importance, except when
they are the source of the spectacular Burmese gem
peridot, which rivals that from Zabargad (St. John's
Island), Egypt. The peridotite in the Bemardmyo
area is a light-colored, granular rock composed almost entirely of olivine with minor pyroxene andmagnetite (Iyer, 1953).In the peridot diggings, therock is generally seen only as a series of loose,
weathered boulders with serpentinization taking
place along fracture surfaces. Also included as a

214

The Rubies of Burma

Figure 3. Detailed
geologic map of the
Mogok Stone Tract of
Burma, adapted fromthe original drawn b y
Clegg and lyer flyer,
1953). Artwork b y
Lisa Ioko.

minor map unit along with the ultramafic intrusives is a small outcrop of nepheline syenite about
12 km west of Mogok.
The marble is generally very coarsely crystallized and typically is pure white in color, although
locally it may be tinged with yellow or pink. In
addition to ruby and spinel, the marble contains
diopside, phlogopite, forsterite, chondrodite,scapolite, sphene, garnet, and graphite. The marbles have been intruded by granitic rocks, and theeffects of contact metamorphism are evidenced by
the presence of feldspar and diopside in very
coarse-grained portions where in contact with thegranitic rocks.
La Touche (1913)included the marbles as partof the Mogok gneiss; Iyer (1953)chose to place themarbles in the "Mogok Series," restricting the
Mogok gneiss to gneisses and unclassified crystalline rocks. These unclassified crystalline rocks
consist of gneisses, granites, and quartz veins that,
because of the thick soil horizon and dense jungle,
could not be mapped as separate units.
In the valleys and on the sides of the hills, thegem-bearing gravel layer rests on a soft, decomposed rock of characteristic appearance. This
gem-bearing bed consists for the most part ofbrown or yellow, more or less firm, clayey, and attimes sandy material, known locally as byon

GEMS & GEMOLOGY

Winter 1983

(Cecil, 1928). This layer, the residuum left by solution of the marble during weathering, contains
ruby, sapphire, and other varieties of colored corundum, as well as spinel, quartz, tourmaline,
feldspar grains, nodules of weathered pyrite, andother minerals of lesser importance. Rarely, a puregem sand occurs, which consists almost entirely ofminute, sparkling grains of ruby. The byon lies, asa rule, from 5 to 6 m below the surface of the valley
floor, and is from 1 to 2 m in thickness, pinching
off to nil. On the sides of the valley the beds of byon
are as thick as 15 to 22 m. These are, of course,
purely residual weathering deposits (Chhibber,1934a).
MINING METHODS
After the departure of the British and their modernmining techniques, native mining was very active,
with operations varying in size from single
operators to mines employing two to threedozen workers.
The indigenous mining methods used at
Mogok have been described i n great detail(Simpson; 1922; Adams, 1926; Halford-Watkins,
1932; Iyer,' 1953; Spaulding, 1956; Ehrmann, 1957;
Meen, 1965; Gubelin, 1965). The three mostcommon mining methods described by these authors include the twinlon (twin), the hmyadwin(hmyaw),and the loodwin (loo).
A twinlon, usually constructed in the dry season, consists of a small circular pit that in generalis less than one meter in diameter. These pits are-

The Rubies of Burmacommonly 6 to 12 m deep, although some as deepas 30 m have been reported (Halford-Watkins,
1932). The pits are dug vertically until the gem
gravel or byon is reached. The miners then dig
laterally for about a 10- to 12-meter radius to remove the gem-bearing gravel. The pits are illuminated by means of a mirror from above. Commonly, three men are employed in a single twinIon: two men dig while the third hauls up the earth
using a long bamboo crane with a basket attached(figure4).This method is not unlike that employedat the Ban Kha Cha sapphire deposit near Chanthaburi, Thailand (Keller, 1983). Occasionally,
when water is a problem, a lebin is constructed. A
lebin consists of a square pit that is 1 to 2 m wide
and reinforced with timber. Water is removed via anative-constructed bamboo pump. The recovered
gem gravels are then carefully washed and sorted
on the surface.
The second most common method of recovering gems at Mogolz is by means of a quarry-likehmyadwin, or hmyaw. These open-pit mines areusually worked during the rainy season, since they
employ hydraulic mining and require a great dealof water. A hmyadwin is dug into a hillside to adepth from 6 to 15 m. Hmyadwins are usually used
continuously for 50 or 60 years because of theirvery complicated construction. They vary greatly
in size, but the most complex is the kind that uses
a series of channels to bring in water from great
distances to wash the soil and gem gravels removed from open-pit mining on the hillside. The

Figure 4. A twinlon, or circular
pit, from which gem-bearing
gravel is removed via the basket
attached 10 the long bamboo
crane shown here.

GEMS & GEMOLOGY

Winter 1983

215

Figure 5. A recovery and washing plant for gem
gravels near Mogok.

gravels and much lighter wastes are washed into
flat circular stone pits, where the "heavies" aretrapped in a series of sluices. The lighter wastes are
washed into the valley below. During operation,
large pebbles are picked out and discarded, andthe sluices are periodically inspected for gems
(figure 5).
Deep chemical weathering in the limestone
areas of Mogok produces typical karst topography,
resulting in numerous underground caverns which
may go for hundreds of meters and contain hugechambers lined with spectacular stalactites andstalagmites. Such caverns, called loodwins or loos,
may also contain some of the richest gem gravels
in the Mogok Stone Tract. Unfortunately, mining
in these caverns is the most dangerous of the threemethods. A miner must find his way through very
narrow channels in the limestone, digging in every
crevice for gem gravel which he puts in a basket
dragged on his foot. When the basket is full, it isbrought to the surface and the gravel is washed.
Because of natural concentration in the loos, suchgravel may contain up to 25% ruby (Chhibber,1934b).However, it is not uncommon for a miner
to get stuck in the rocks, or lost underground.
Because of this danger, as well as the depletion ofaccessible loos, this method has been used only
rarely in recent years.
As is the practice in most of the gem-producing
areas of the world, once the miner finishes processing his gravel and abandons it, i t is freely available
to the small independent miner (figure 6), who
may reprocess i t in the hope of finding overlooked
Figure 6. As is the case inmost gem-mining operations,
the waste from the major mining
operations is freely available toindependent miners for sorting.
In Burma, however, this sortingis limited to females, known
locally as kanase.

216

The Rubies of Burma

GEMS & GEMOLOGY

Winter 1983

I
Figure 7. Exsolution crystals o f rutile i n a
Burmese ruby. Such dense clouds of short,
flattened rutile needles are commonly observedin rubies from Burma. Oblique illumination,
magnified 60 X. Photonlicrograph b yJohn Koivula.

gem material. In the case of Mogolz, however, only
women are allowed to search for gems in such
refuse. These women, called kanase, usually recover only enough from the debris to live on, butthey have been known to recover large gems.

GEMOLOGY

OF THEBURMESE RUBY
The physical and optical properties of the rubies
from Mogok do not differ significantly from thoselisted for corundum from other sources. Anderson(1980)lists refractive indices for Burmese rubies of
1.765 and 1.773, with a birefringence of 0.008 and a
specific gravity range of 3.99 to 4.00. These rubies
have particularly strong dichroism, with the twocolors being pale yellowish red and deep red. The
Burmese material is chrome-rich, which gives rise
to strong fluorescence to ultraviolet radiation anda characteristic absorption spectrum, as well as tothe "pigeon's blood" color associated with Burmese stones. The absorption spectrum characteristically consists of a bright doublet in the red at
6942 A and 6928 A, and weaker lines in the orange
at 6680 A and 6592 A.
Inclusions do tend to be of some use in distinguishing Burmese rubies from those of otherlocalities. According to Webster (19801, Burmese
rubies exhibit short rutile needles, parallel to eachof the three parallel faces of the hexagonal prism.
These needles intersect at 60Âand 120Â°and lie in aplane 90Â°fro the c-axis of the crystal (figure 7).In
addition, Burmese rubies may contain included
crystals of rutile, spinel, or biotite. Most characteristic of rubies found in Burma are inclusions of

The Rubies of Burma

Figure 8. This characteristic inclusion scene i n a
Burmese ruby shows "bloody" deep red and fine,
short, acicular, dust-like crystals of rutile, as wellas whitish and colorless calcites, a111 against acolor-zoned field of variable intensity. Dark-field
and oblique illumination. Magnified 50 x.
Photomicrograph by John Koivula.

calcite rhombs, an artifact of the marble host rock(figure 8).Both Koivula (personal communication)
and Eppler (1976)-havefound negative crystals to
be very common in Burma rubies (figure 9), andKoivula has also noted sphalerite crystals.

FAMOUS RUBIES FROM MOGOK
Unlike diamond, emerald, and sapphire, fine,well-publicized faceted Burmese rubies are almost
unknown. There are, in fact, few if any named
rubies in the museums or royal treasuries of theworld today. The gemological literature of the
Figure 9. A primary negative crystal in a Burmese
ruby. Such negative crystals, although somewhat common, are often mistaken for solid
itic1usion.s and therefore go unrecognized andoverlooked. Shadowing, magnified 65 x. Photomicrograph b y John Koivula.

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217

20th century does note a handful of stones exceeding five carats, but with the exception of two-the
43-ct Peace ruby and the approximately 40-ct
Chhatrapati Manick (Clarke, 1933)-no others
were significant enough to bear names, and even
the whereabouts of the two named stones is
unknown today.
In 1875, owing to the impoverished conditionof the ruling house of Burma, two spectacular rubies were placed on the market. After cutting,these stones weighed 32.35 and 38.55 ct. Seldom
have two such remarkable and perfect rubies appeared on the European market simultaneously.
These two stones brought Â£0,000 and Â£20,000
respectively. At the time, many regarded this incident as only an indicator of the quality and size ofthe gems that the ruling houses of these Eastern
empires must possess. Yet, when the British conFigure 10. One of the finest Burmeseruby crystals
ever placed on public display is this 196.1-ct
etched crystal, which is n o w part of thepermanent collection of the Los Angeles County
Musum of Natural History. Photo 01 983 Harold
and Erica Van Pelt.

quered and annexed Burma, they found little or noevidence of vast stores of corundum gems, although the possibility exists that all the royalgems were stolen during the conquest of thecountry, by both the Burmese and the English(Brown, 1934).
Years later, in 1899, a 77-ct rough ruby was
discovered by Burma Ruby Mines, Ltd. The most
famous Burma ruby was found on Armistice Day,
November 11, 1918. Two English mine supervisors spotted the stone on the washing pan andcalled for the mine's general manager, who subsequently named it the Peace ruby (Keely, 1982).The
43-ct crystal reportedly was purchased by awealthy Mogok stone merchant who cut it into a
22-ct flawless stone. Unfortunately, its color tone
was slightly dark and the cut gem sold for less thanthe dealer had paid for the crystal. Since the discovery of the Peace ruby, several stones of nearly
30 ct have been found, although none has received
a special name that has been carried into theliterature.
Today, fine Burmese rubies are almost nonexistent in museum collections. The British
Museum of Natural History at South Kensington
displays the 167-ct Edwardes ruby crystal, which
was given to that museum by John Ruslzin in 1887
(Spencer, 1934).The crystal is not of faceting quality, but must be considered one of the more important Burmese rubies surviving today. The Los Angeles County Museum of Natural History displays
Figure 11. This 15.97-ct cushion-cut ruby from
the Mogok Stone Tract is considered t o be one of
the finest Burmese rubies known today. Propertyof Alan Caplan, New York City, Photo by
Morris Lane.

218

The Rubies of Burma

GEMS & GEMOLOGY

Winter 1983

the 196.1-ct Hixon ruby. This highly etched crystal is of superb color and possesses unusuallycomplete crystal form (figure 10). Alan Caplan, a
New York gem dealer, has a magnificent 15.97-ct
faceted Burma ruby that many believe is one of thefinest rubies of its kind. It is exceptionally free offlaws and has the classic "pigeon's blood" color(figure 11).It was displayed recently at the American Museum of Natural History in New York.
CONCLUSION
The Mogolz Stone Tract is a classic example of theuncertainties inherent in the mining of colored

REFERENCES
Adams F.D. (1926) A visit to the gem districts o f Ceylon andBurma. Bulletin of the Canadian Institute of Mining andMetallurgy, No. 166, pp. 213-246.
Anderson B.W. (1980) Gem Testing. Butterworths, London,
England.
Bleeck A.W.C. (1908)Rubies in the Kachin Hills, Upper Burma.
Records o f the Geological Survey o f India, Vol. 36, pp.
164-170.
Brown C.B., Ju,dd J.W.(1896)The rubies of Burma and associated minerals; their mode of occurrence, origin and metamorphoses: a contribution to the history o f corundum.
Philosophical Transactions of the Royal Society o f London,
Series A, Vol. 187, pp. 151-228.
Brown J.C. (1933)Ruby mining in Upper Burma. Mineralogical
Magazine and Journal of the Mineralogical Society, Vol.48,
No. 6, pp. 329-340,
Brown J.C.(1934)Mining rubies in Burma. Gemmologist, Vol.
3, NO. 31. pp. 199-203.
Calhoun A.B. (1929)Burma-an important source o f preciousand semiprecious gems. Engineering and Mining Journal,
Vol. 127, No. 18, pp. 708-712.
Cecil C.(1928)Ruby mining in Burma. Engineering and Mining
Journal, Vol. 127, No. 8 p. 294.
Chhibber H.L. (1934a)The Geology of Burma. Macmillan andCo., London, England.
Chhibber H.L. (1934b) The Mineral Resources of Burma.
Macmillan and Co., London, England.
ClarkeV. (1933)Thestory o f an Indian ruby. Gemmologist, Vol.
2, pp. 148-153.
dlAmato P.G. (1833) A short description o f the mines o f precious stones in the district o f Kyatpyin, in the Kingdom ofAva. Journal of the Asiatic Society of Bengal, Vol. 2, pp.
75-76.Ehrmann M. (1957)G e m mining in Burma. Gems a ) Gemology,
Vol. 9, No. 1, pp. 3-30.
Eppler W.F. (1976)Negative crystals in ruby from Burma. lourrial of Gemmology, Vol. 15, No. 1, pp. 1-5.
Fermor L.L. (1930) Mineral production o f India during 1929.
Records of the Geological Survey o f India, Vol. 63, Part 3,
pp. 281-357.
Fermor L.L. I1931 1 Moeok stone tract. Katha district. Records o f
the ~ e o l ' o ~ i csurvey
alof India, V O I .65, Part 1, pp. 80-86,
90-95.
. - .-

Fermor L.L. (1932)The Mogok stone tract, Katha district. Records of the Geological Survey of India, Vol. 66, Part 1, pp.
92-96.

T h e Rubies o f Burma

gems. This deposit has been known to produce
relatively large amounts of rubies of the finest
quality. In addition, the geology of the area and theslowness of the relatively primitive mining
methods suggest that the supply of Mogolz rubies
should be far from depleted. Yet fine Burma rubies
are rarely encountered in today's gem markets andthe number of rubies offered at the annual gem
emporium in Rangoon appear to have dwindled toinsignificance because of the political uncertaintyof that area of the world. It remains to be seen
whether the true potential of the Mogolz area will
ever be realized.

Fermor L.L. (1934) Mogok stone tract. Records of the Geological Survey of India, Vol. 68, Part 1, pp. 50-58.
Fermor L.L. (1935) Mogok stone tract. Records of the Geological Survey of India, Vol. 69, Part 1, pp. 50-54.
Cordon R. (1888)On the ruby mines near Mogok, Burma. Proceedings of the Royal Geographic Society, Vol. 10, pp.
261-275.
Gubelin E. (1965)T h e ruby mines in Mogolz, Burma. Journal ofGemmology, Vol. 9, No. 12, pp. 411-427.
Halford-Watkins I.F. (19321Methods of ruby mining i n Burma.
~ e m m o l o ~ i s t . ' ~1,oNlO. . 11, pp. 335-342; andNo. 12, pp.
367-373.
Heron A.M. (1936) Mogok stone tract. Records of the Geological Survey o f India, Vol. 71, Part 1, pp. 58-63.
Heron A.M. (1937)Age o f Mogok series. Records of the Geological Survey of India, Vol. 72, Part 1, p. 62.
Iyer L.A.N. (1953)The geology and gem-stones of the Mogok
stone tract, Burma. Memoirs of the Geological Survey ofIndia, Vol. 82, p. 100.
Keely H.H. (1982)T h e ruby mines of Burma. Gems, Vol. 14, No.
3, pp. 6-11; NO. 4, pp. 10-14.
Keller P.C. (1982)The Chanthaburi-Trat gem field, Thailand.
Gems a ) Gemology, Vol. 18, No. 4, pp. 186-196.
La Touche T.H.D. (1913)Geology of the northern Shan states.
Memoirs of the Geological Survey of India, Vol. 39, Part 2,
p. 379.
Meen M.A. (1962) G e m hunting in Burma. Lapidary lournal,
Vol. 16, No. 7, pp. 636-653.
Mineral Resources (1886) United States Geological Survey,
Washington, D.C.
Morgan A.H. (1904)T h e ruby mines o f Burma. Mining Journal,
Vol. 16, p. 4,
Nordland R. (1982)On the treacherous trail to the rare ruby red.
Asia, Vol. 5, No. 3, pp. 34-55.
Scott W.H. (1936)T h e ruby mines o f Burma. Gems a ) Gemology, Vol. 2, No. 1, pp. 3-6.
Siinpson R.R. (1922)Notes on a visit to the Burma ruby mines.
Transactions of the Mining and Geological Institute, Vol.
17, Part 1, pp. 42-58.
Spau1dingD.L. (1956)T h e ruby mines of Mogok, Burma. Gems
a1 Gemology, Vol. 8, No. 11, pp. 335-342.
Spencer L.J. (1933) Nation acquires large ruby. Gemmologist,
Vol. 2, No. 18, pp. 176- 178.
Webster R. (1975) Gems: Their Sources, Descriptions, andIdentification, 3rd ed. Butterworths, London, England,
Wynne T.T. (1897)T h e ruby mines o f Burma. Transactions ofthelnstituteof MiningandMetallurgy, Vol.5, pp. 161- 175.
- -

-

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NOTESA N D

NEW TECHNIQUESINDUCED FINGERPRINTSBy John I. KoivulaO v e r t h e past f e w years, numerous Verneuil-type(flame fusion) synthetic sapphires a n d rubies w i t hsomewhat natural-appearing induced fingerprint i n clusions have surfaced i n t h e trade. T h i s article reportst h e results of a series of experiments conducted t o
explain t h e phenomenon of i n d u c e d fingerprints a n d
h o w they are produced i n gemstones generally a n d i nflame-fusion synthetic c o r u n d u m specifically.

Since 1980, the presence of somewhat naturallooking fingerprint inclusions in flame-fusion synthetic corundums has haunted the colored stone
industry. After the first report in the literature(Crowningshield, 1980) of this new treatment, a
number of treatment-related articles appeared invarious gemological and jewelry trade publications. These articles detailed most of the treatment processes, such as diffusion, used on rubies
and sapphires, but they only briefly mentioned
induced fingerprints. In two excellent articles onheat and diffusion treatment of natural and synthetic sapphires (Crowningshield and Nassau,
1981; Nassau, 1981), the mechanisms used toinduce fingerprints are described as unknown.
However, the statement by Nassau (1981) that
"according to some unsubstantiated reports, aflux-type chemical such as sodium carbonate orborax may assist in this process" provided an important clue to the production of induced fingerprints. Another important clue is given by C. R.
Beesley (19831, who stated that "an outgrowth [ofheating synthetic sapphire] was to induce frac-220

Notes and New Techniquestures from the surface of the material [synthetic
sapphire], then force some material into the fractures which could be almost crystallized during
heating. This gives the appearance of a natural
fingerprint." The statement concerning the fractures induced from the surface is significant (although the comment about some material being
forced into the fractures which could be almost
crystallized during heating, is confusing at best).
To better understand and clarify the mysterysurrounding "induced fingerprints," the author
performed a series of "before and after" heating
experiments on flame-fusion rubies that werebased on observations made on natural fingerprints and those found in flux and hydrothermallygrown synthetic gemstones. The results of theseexperiments are reported below.

ABOUT THE AUTHOR
Mr. Koivula is senior gemologist in the Applied Gemology
Department of the Gemological Institute of America, Santa
Monica, CA.
Acknowledgments: The author is most grateful to Thomas H.
Chatham of Chatham Created Gems, San Francisco, who,
through his cooperation in the healing experiments, proved theauthor's theory. Mark Mann, supervisor of the GIA Jewelry
Arts Course, was very helpful in the fusion fingerprint experiment. Thanks are also extended to Chuck Fryer, GIA Santa
Monica, for helpful discussions; to Robert Kane, Gem Trade
Laboratory, Inc., Los Angeles, for the study-loan of two fluxhealed flame-fusionsynthetic rubies with induced fingerprints; toWilliam Kerr, GIA Santa Monica, for faceting the crystal after
regrowth; and to Ruth Patchick for typing this manuscript. Lisa
Joko prepared the line drawings. All photographs, unless otherwise captioned, are by the author.
0 7984 Gemological Institute of America

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Figure 1. The fracture step in the production of fingerprint inclusions. The
example shown hereis a conchoidal fracture in a colorless beryl. Oblique illumination, magnified35 X. Drawing by Lisa
foko after Roedder, 1962.

HOW DOES A FINGERPRINTINCLUSION FORM?
The most important clue to understanding induced fingerprints lies in the very name we havegiven them. In both natural and synthetic gemstones, fingerprint inclusions have been induced,that is, stimulated by internal and external forces
acting on - t h e crystallized host material. The
mechanism behind natural fingerprints is well
documented in the literature (see, for example,
Eppler, 1959, 1966; and Roedder, 1962, 1982).This
knowledge of how the process occurs in nature is
helpful to our understanding of the synthetic production of similar inclusions.
When a crystal is fractured (figure 11, the fracture instantly becomes a vacuum, drawing inwhatever surrounds it to alleviate the negative
pressure. Capillarity provides further impetus in
drawing fluids into the break. If the crystal is evenslightly soluble in the fluids surrounding it, repairof the fracture will begin immediately. The morekinetic energy, in the form of heat, supplied during
the healing process, the faster the fracture will
heal. Heat is (1)generated by sources outside thecrystal, such as igneous or metamorphic activityor the heat generated by pressure commonly associated with burial at depth in the earth; and (21released by the crystal itself, as it seeks to regain
crystallographic equilibrium (upset by the increase in potential energy of the fracture zone created by the additional surface area exposed) andreturn to a lower energy state.
Provided the fractured crystal is in a repair
environment, as it starts to heal itself individual
atoms or groups of atoms will leave an area of highenergy on the fracture surface and redeposit on aNotes and New Techniquessurface of lower energy, releasing their heat of
crystallization in the process. Molecule by molecule this process continues. Material is dissolved
from both the convex and flat portions of the fracture walls and redeposited in the concave areas,
gradually trapping small volumes of the repair
fluid. Trapping 'occurs between recrystallized
walls, pillars, and columns that have formed, likethe adjoining stalagmite and stalactite pillars in acavern, between the opposing surfaces of the fracture. These fluid islands are often interconnectedby a series of fine tubes termed communication
tubes. So many of these communication tubes
may be interconnected that a fishnet-like pattern
results. This intermediate stage in the healing process is shown in figure 2.
If healing continues, the communication
tubes will gradually thin out in certain areas, gain
volume in others, and eventually separate into
numerous smaller fluid-filled cavities all lined up
along the original path of the pre-existing communication tube. This process is called necking
down. Necking down continues throughout theentire original fracture zone, as numerous smaller
fluid inclusions are formed from a few larger ones.
Ultimately we are left with a uniformly arranged
grouping of small fluid-filled voids that occupy thesame space as the original fracture. The resulting
healed fracture has now taken on the appearance ofa "fingerprint," composed of numerous dots orislands. Each of the dots that so geometricallymake up the total fingerprint is in fact a separate
and distinct fluid inclusion, as portrayed in figure
3. The process of forming a fingerprint inclusion inany crystalline material, synthetic or natural,
should be the same. The environment of growth

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221

Figure 2. This aquamarine illustrates
the intermediate, communicationtube-forming stage i n the healing of fractines. Transmitted and oblique jll~imination, magnified 60 X. Drawing b y Lisa
Joko after Roedder, 1962.

and the fluids used to transport the atoms required
to heal a fracture may be different, but the stepby-step process, as shown in figures 1 through 3,
does not change.

THE THEORY BEHIND THE
FORMATION OF INDUCED FINGERPRINTSIN FLAME-FUSION SYNTHETICSAll gemologists have studied fingerprint inclusions in natural gemstones, as well as in flux andhydrothermally grown synthetics. But gems synthetically grown from a melt by the Verneuil
flame-fusion method or by the Czochralski
crystal-pulling process are not products of environments that produce crystals with healed fractures. Yet synthetic corundums cut from Verneuiland Czochralslzi melt crystals containing induced

fingerprints have been mistakenly purchased as
the more expensive flux synthetic rubies, and evenas natural rubies and sapphires. Quite often parcelsof corundums will be found to contain some ofthese synthetics with induced fingerprints. How
are fingerprint inclusions placed in such synthetic
crystals?
Corundum is corundum regardless of the environment in which it is grown. If we were to take a
gem cut from a synthetic melt crystal and thermally shock it to produce fractures, then place it ina synthetic growth environment, such as a fluxgrowth bath, surrounded by a fluid in which thecorundum is at least partially soluble, the induced
fractures should, over a period of time, heal themselves, turning into induced fingerprint inclusions. The following experiments were carried out
to test this theory.

Figure 3. A golden beryl demonstrates
the third and final step i n fingerprint
formation. N o w the communication
tubes have necked down to form individual fluid inclusion islands. Transmit.
byted light, magnified 1 0 0 ~Drawing
Lisa /oko after Roedder, 1962.

222

Notes and New Techniques

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PRODUCTION OF
INDUCED FINGERPRINTSVerneuil material (figure4) was selected for testing
because it was more readily available than the
Czochralski pulled synthetic. A flat, windowlilze
configuration was chosen for the experimental
synthetic rubies because of the ease with which
they could be studied under the microscope. Threesubjects were heated and then quench-crackled incold water, resulting in badly fractured slabs. Oneof these is illustrated in figure 5.
Each of the three fractured synthetic rubies
was then designated for a separate experiment asfollows: (1)fingerprints induced through flux healing (the most important of the three experiments),

A SIMPLE EXPERIMENTFOR INDUCING FINGERPRINTINCLUSIONS

T

here is a simple experiment that anyone cando'to' test the mechanism of fingerprint formation and actually observe the step-by-step repair process first hand. All that is needed is water,a good supply of a highly water-soluble salt such asalum or sodium chloride (common table salt), atleast one transparent single crystal of the chosensalt weighing 2 ct or more that you have studied
carefully under the microscope before beginningthe experiment, and a source of heat such as a
kitchen stove. First, prepare a boilingsupersaturated solution of the salt in water. Pour
only the liquid portion off, leaving the excess undissolved salt behind. While keeping the solution
very hot, supercool your test crystal(s) using afreezer, an alcohol and dry ice solution, or, if you
have access to a cryogenically liquefied gas such as
liquid nitrogen, use that.
Once the crystal(s)are very cold and the solution is hot, plunge the crystal(s]into the solution.
This will cause the crystal(s)first to fracture in thegrowth-nutrient-rich salt solution and then to
begin healing virtually immediately. Now allow
the solution to cool gradually. At first some dissolving of the crystal(s)surfaces may be noticed,
but quickly the process will reverse itself and the
crystal(s1 will begin growing. Remove the cryst a l [ ~ from)the solution periodically and study
them under the microscope. Fingerprint inclusions will be observed forming where the fractures
once were.

Notes and New Techniques

Figure 4. A flame-fusion synthetic ruby b o d esimilar to the material used in the experiments.
Photo b y Mike Havsiad.

(2)fingerprints induced by secondary fusion, and(3)induced chemical dendrites.

Fingerprints Induced Through Flux Healing. After
carefully documenting the appearance of the fractured synthetic rubies (again, see figure 5), the author mailed one of the stones to Thomas H.
Chatham, president of Chatham Created Gems, in
San Francisco. Mr. Chatham had volunteered toplace this test subject in a flux-growth environment in an attempt to heal the fractures. A platinum wire affixed to the synthetic ruby slab provided a convenient means of transporting the test
subject into and out of the growth chamber. The
regrowth time was 42 days (Chatham, personalcommunication, 1983).The result is shown in figure 6. Note the remnants of the platinum wire at
the base of the crystal.
To prepare the regrown mass for study, theauthor first sawed off the two ends and then hadthem polished so the thickness of the overgrowth
could be observed (figure 7). Already it was apparent that fingerprints were present throughout theovergrown Verneuil subject. Next the crystal was

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Figure 5. A quench-craclilecl synthetic ruby wind o w used for flux healing (14.2 x 12.0 x 3.0 m m ) .
Photo by Mike Havstad.

completely faceted and the induced fingerprints
were studied. Although it was no longer possible tolocate the exact configuration of fractures shownin figure 5, any number of induced fingerprints
were available for photomicrography. One of theseis shown in figure 8 together with the curved striae
characteristic of the synthetic material. The author also examined two other large Verneuil boule
sections with flux ruby overgrowths prepared by
Chatham Created Gems (figure 9). These were
found to contain numerous flux regrowth induced
fingerprints as well.
Inducing Fingerprints by Secondary Fusion. In thesecond experiment, to see if heat alone could induce pseudo-healing, one of the prefractured syn-Figure 6. V e r n e ~ ~synthetic
ilruby slab after flux
regrowth for42 days(20.7 x 16.8 x 7.6mm). Notethe platinum wire at the base. Photo b y Mike
Havstacl,

thetic rubies was placed on a charcoal block and ajeweler's torch was used to melt and recrystallize
it several times. Although the overall appearanceof the melted mass was not an attractive sight, andon cooling numerous additional unwanted fractures appeared, a few somewhat fingerprint-likeinclusions were observed.
Induced Chemical Dendrites. The third and lastexperiment resulted from observations, by the author, of a flame-fusion ruby that had fractures decorated by a crystalline chemical with a melting
point just over 100Â°CThis low melting point
made it possible to melt and recrystallize the contents of the fractures until a desirable, somewhat

Figure 7. Cross-sectional view
through the end o f the experimental
synthetic ruby illustrated i n figure 6.
Note the outline of the flux ruby layerover the flame-fusion core. Some fingerprints are visible even at this l o w
magnification. Oblique and transmitted light, magnified 5 X.

224

Notes and New Techniques

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Figure 8. Induced flux fingerprint produced~hro~zgl7
experimen LOtion in a Verneuil flamefusion synthetic ruby together with the characteristic curved striae. Shadowing, magnified 45 X.

Figure 9. T w o Veri7euil flame-ftzsion ruby bouleyBoth ofsections with Q thin f l u x r ~ ~ bovergrowth.
these samples contained numerous induced fingerprints. The larges~sample is approxjmately 5c m long. P h o ~ ob y Mike Havstad.

natural-appearing dendritic form was obtained.
The low melting point of this unlznown chemical suggested that it inight be organic in nature.
Figure 10. Acetanilide chemical stain decorating
Although the author had access to two organica fracture plane i n a Verneuil synthetic ruby.
crystalline compounds with similarly low melting
Dark-field and oblique illumination, magnified 80 x,
points! acetanilide (melting point} 114OC; boilingpoint! 304OCJ and resorcinol (melting point}
111Â°Cboiling point, 178OC)acetanilide was chosen for the experiment because of its greater melting point to boiling point spread andl therefore,
less cruciql temperature control.
The prefractured synthetic ruby was heatedover a Bunsen burner to create a vacuum in thefractures through rarefaction. The heated ruby wasthen quenched in enough premelted a~etanilide~contained in a test tubel to completely submerse
the ruby. The acetanilide was allowed to crystallize and then was remelted and poured off. The
ruby was cleaned and then studied under the
microscope. One of the resulting patterns decorating the fractures is reproduced in figure 10.

WHO PRODUCES THESE SYNTHETICS
WITH INDUCED FINGERPRINTS?
On the basis of the author's observations/ it islilzely that those synthetic rubies and sapphiresthat appear in the trade with induced fingerprint
inclusions, such as the one shown in figure 11, areprobably not healed in a well-controlled fluxgrowth furnace. Rathert they are probably thesometimes accidental result of clever but often
crude heat treatments carried out! both in Thailand and Sri Lanlza! on synthetic rubies and various
colors of synthetic sapphires in the attempt todissipate the curved color and growth zoning.
.During heat treatment in these countries/ it isNotes and New Techniques

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225

F I ~ L1 1I . ~Borax~(!) iniluced fingerpr~ntIn a flame-/usIon synthetic sapphire. Dark-field and oblique
illumination, magnified 65 X.

common practice to use borax or a borax-based
solution, purportedly on the outside of the crucible
holding the stones (Abraham, 1982). Any slzilled
bench jeweler or gemologist lznows that corundum
becomes soluble in borax at elevated temperatures. That is to say) borax acts as a flux to thecorundum; it is an agent capable of promoting
quiclz healing in any fractures-whether placed
accidentally or on purpose-that may be present.
The mechanism of fracture repair at worlz in thesecases is the same three-step process described earlier for natural stones.
IDENTIFYING GEMS WITH
INDUCED FINGERPRINTSFor some time gemologists have lznown that unless one is very slzilled in the study of inclusions, it
is no longer possible to say a gemstone is natural
merely because it contains fingerprint inclusions.
Now) however) with the presence of induced fingerprints in Verneuil and Czochralslzi synthetic
corundum, the question is not only whether thegem is natural or synthetic, but if it is synthetic, is
it a more costly flux-grown synthetic or is it an
upgraded flame-fusion or pulled synthetic with induced fingerprints?
There is no question that recognizing induced
fingerprint inclusions can be a problem. When fingerprint inclusions that reach the surface are theonly immediately observable internal characteristics, be suspicious. Checlz the gem in question
for color zoning both by diffused transmitted lightand by immersion in methylene iodide. The presence of curved color zoning together with fingerprint inclusions would tell you that the finger-

Notes and New Techniques

prints have been induced into a synthetic stone.
The presence of curved striae in conjunction with
fingerprint inclusions in synthetic rubies andsome synthetic sapphires is a sure sign that aflame-fusion gem has been doctored. Gas bubbles
are another clue to the less expensive synthetics.
With the above clues) treated synthetic rubies
and sapphires grown by the Verneuil flame-fusion
process are easily spotted. However, gems cut from
Czochralslzi pulled crystals rarely have any recognizable inclusions: quite often they are essentially flawless. Therefore) gems with fingerprint
inclusions that are otherwise flawless should betreated with the highest suspicion. Straight or
sharply angular growth and color zoning and recognizable included crystals are important clues
that a gem is not a melt-grown Verneuil or Czochralslzi synthetic.
CONCLUSION:WITH THOUGHTS TO THE FUTURE
Of the three experiments conducted, experiment
1, regrowth in a flux environment, performed at
the Chatham laboratories in San Francisco, was by
far the most successful.
Although the introduction of organic chemical
dendrites into pre-existing fractures proved both
successful and interesting, the dendrites achievedin experiment 3 in no way resembled or could be
mistalzen for fingerprint inclusions. Problems
could result) however, for gemologists who, in thepast, have considered dendrites a sign of natural
origin. The attempt to produce fingerprints
through secondary fusion met with very little success. Although some inclusions were produced

GEMS & GEMOLOGY

Winter 1983<that slightly resembled fingerprints! they were few
and far between) and were always accompanied bynumerous unrepaired fractures! areas containing
large gas bubbles! and zones of translucent cloudy
material. Or! in a few words! they were useless as
gemstones. However! flux regrowth was) as expected by the author! a complete success. All of thefractures showed fingerprint-healing patterns.
Once the regrowth layer was removed! the remaining material! containing the induced fingerprints!
could easily have been cut into gemstones.
Possible future applications for this and similar techniques are interesting! to say the least. If
the technology that exists to repair fractures today
is further refined! we might someday encountersynthetically repaired natural gem materials.
In his excellent boolz G e m s M a d e By M a n ,Kurt Nassau shows before and after photographs ofa Japan-law twin of quartz that was broken andsubsequently successfully repaired syntheticallyby Giorgio Spezia . . . the year was 1908, In more
recent work (Shelton and Orville, 1980)!synthetic
fingerprint inclusions were produced hydrothermally in natural quartz. Imagine in the future

if we had the ability to hydrothermally repair a
ruby! emerald! or sapphire that had been accidentally fractured during setting! repair! or cutting.
Surely a fingerprint inclusion is infinitely moredesirable-and infinitely more durable-than afracture.
In spite of the future potential for good! thelogical application today of induced fingerprints is
to upgrade less expensive Verneuil flame-fusion
and Czochralslzi pulled synthetic corundums sothat they may be sold to the unsuspecting tradeeither as more costly flux-grown synthetics oreven as natural gems.
Because of this! induced fingerprints! whether
intentionally or accidentally produced! represent a
type of treatment that must be dsclosed. A treatment of this type should concern not only thegemologist and the jeweler! but also those involved in the flux growth of synthetic gems as
well, because the presence of such a treated material on the marlzet could seriously undermine thesale of their products. It is only through mutual
cooperation between gemologists and crystal
growers that such a problem can be dealt with.

REFERENCES

Eppler W.F. (19661The origin of negative crystals in gemstones.
/ournal of Gemmology, Vol. 10, No. 2, pp. 49-56.
Nassau K. (1980)Gems Mnde by Man. Chilton Book Co., Radnor, PA.
Nassau K. (19811 Heat treating ruby and sapphire: technicalaspects. Gems ed Ge~nology,Vol. 17, No. 3, pp. 121- 131.
ltocdder E. (19621Ancient fluids in crystals. Scientific American, Vol. 207, No. 4, pp. 38-47.
Roedder E. (1982) Fluid inclusions in gemstones: valuable defects. In the Intern~ztionalGemological Symposic~mProceedings, Gemological li~stituteof America, Santa Monica,CA, pp. 479-502.
Shelton K.L., Orville P.M. (19801Formati011 of synthetic fluidinclusions in natural quartz. American Mineralogist, Vol.
65, No. 11 and 12, pp. 123-1236.

Abraham J.S.D. (1982) Hcat treating con~ndum:the Bangkok
operation. Gems ed Gemology, Vol. 18, No. 2, pp. 79-82.
Beesley C.R. (1983) What you must l~now,a primer 011 treatMay, p. 5 1.
ment ID. \eweler's Circ~~lar-Keystone,
Crowningshield R. (1980) Corundum o b s e ~ a t i o n sand problems. In Developments and Highlights at G1AfsLab in New
York, Gems cd Gemology, Vol. 16, No. 9, pp. 315-316.
Crowningshicld R., Nassau K. (1981)Thc heat and diffusion
treatment of natural and synthetic sapphires. Iourr~alofCe~nmology,Vol. 17, No. 8, pp. 528-541.
Eppler W.F. (19591The origin of healing fissures in gemstones.
/ourno1 of Gemmology, Vol. 7, No. 2, pp. 40-66.

Notes and New Techniques

GEMS & GEMOLOGY

Winter 1983

227

COBALT GLASS AS A LAPIS LAZULI IMITATIONB y George Bosshart
A ~lecl<laceof round beads offered as "blue quartz from
India" was analyzed by gemological and addition~~ladvanced techniques. The violet-blue ornamental
material, which resembled fine-q~ralitylapis lazuli,~ be a nontransparent cobalt glass, unlil<eturned O L J LO
any glass observed before as a gem substit~zte.The
characteristic color irregularities of lapis (whjtein blue)
had been imjtated by white crystdlites of lowcrjstobalite .ir~cludeclin the deep blue glass.

T h e gemological world is accustomed to seeing
gemstones from new localities, as well as new or
improved synthetic crystals. With this in mind, it
is not surprising that novel gem imitations are also
encountered. One recent example is 'lopalitellla
convincing yet inexpensive plastic imitation ofwhite opal manufactured in Japan. This article describes another gem substitute that recently appeared in the inarlzetplace.
Hearing of an "intense blue quartz from India1'
was intriguing enough to arouse the author's suspicion when a neclzlace of spherical opaqueviolet-blue 8-mm beads was submitted to the SSEF
laboratory for identification. Because blue quartz
in nature is normally gray-blue as a result of thepresence of T i 0 2 (Deer et al.! 1975! p. 2071 or tourmaline fibers (Stalder) 1967)! this particular identification could be immediately rejected. Although synthetic cobalt-colored quartz exists,
thus far it has been produced only in a transparent
form. The beads of the neclzlace we examined resembled more closely a fine lapis lazuli! with thecharacteristic color irregularities of lapis! yet they
displayed a tinge of violet exceeding that of topquality lapis and they contained no pyrite grains.
Accordinglyl a series of gemological and othertests were conducted to determine the precise nature of this unusual material.

RESULTS OF GEMOLOGICAL TESTING
The properties compiled in table 1 clearly indicatethat the material is not lapis lazuli or any othernatural material! but rather a man-made cobaltcolored substancel apparently a glass. While the228

Notes and New T e c h n i q ~ ~ e s

400

500

600

700

Wavelength A (nm)Figure 1. Absorptio~ispectrum of a cobalt glass
imitating lapis lazuli recorded ~hrougha chjp ofapproximately 2.44 i n m thickness in the range of
820 n m 10 300 nm, ot room temperature (PyeUi7jcam SP8-100 Spectrophotometer).

refractive index of the tested material (1.508)does
not differ marlzedly from that of lapis (approximately 1.50)/ its specific gravity of 2.453 issignificantly lower than the average for lapis (approximately 2.80). The absorption spectrum [figure 1)differs from that of a blue-filter glass only by
its slightly stroEger iron pealzs and by a shift in theultraviolet absorption edge from approximately

ABOUT THE AUTHOR
Mr. Bossharl, a mineralogist and gemolog;st, is laboratory director of the Swiss Foundation for the Research of Gemstones(SSEF), Zurich.
Acknowledgments: The author wishes to /hank Dr, W . B. Stern, oflhe Geochemical Laboratory of /he University of Easel, for the
XRF-EDS data; and Dr. H. A. Hanni, also of the Geochemical
Laboratory of the University of Easel and of the SSEF Zurich, /or
providing the X-ray diffraction determination in addition to his
helpful suggest;ons.

0 1984 Gemolog~calInstitute of America

GElMS & GEMOLOGY

Winter 1983

TABLE I . Properties of a cobalt glass imitating lapis lazuli
Property

Description

Violetish blue of strong
saturation
DIN 61 64 color indicesa
15% : 6 : 4 (hue, saturation,
darkness)
Opaque to semitranslucent (inDegree of transparency
thin sections, translucent totransparent)
Absorplion (recorded at room Strong bands at 642, 592,
535 nm (cobalt); faint bands attemperature)
490, 438, 378 nm (iron)Long-wave, extremely weak
U,V, fluorescence
Short-wave: absent
Refractive index, nD
1.508 on a section (spotread~ngsslightly lower)
Isotropic (in thin sections:
Optical character
anomalous extinction)
Vitreous (slightly silky sheen on
inclusions)Apparent porosity
Nonporous
Specific gravity (4OC)
2,453 (one specimen)
Smooth, spherically molded
SurfaceConcho~dalto almost flat, w ~ t hSurface of fractures
fine structure
Waxy to vitreous
Luster of fractures
Both whiteStreak* scritch
Approximately 5Y2
Mohs hardness
Regular c~rcularshrinkages
External characteristics
around drillholes, few subspherical depressions (molding
marks?), and several filled
angular cavities onbead surfaces
White crystallites of micrometer
Internal characteristics
size forming dendritic and large
radiating to stellate patterns, In
most casessurrounded by trarisparent blue areas and emanaling from a grainy center
None to thermal lest tip
Reaction to heat
None
Reaction to ferrornagnetism
None
Reaction to diluted HCI
Si; Ca, Ti, Mn, Fe, Co, Cu, Zn, As
Chemical elements(as detected by energydispersive X-ray
fluorescence)
Color

;

Apart from the band at 490 nm (very weak], noother faint iron bands, recorded by the spectrometer, were detected with the spectroscope.
The photographs in figures 2 and 3, talzen inreflected light, show bands and aggregates of white
inclusions that are essentially of two types. One isa flat dendritic or fernlike array (similar to that infigure 9, "metajade," of Hobbs, 1982). The otherconsists of planes in radiating to stellate patterns
similar to coral septa, with the planes perpendicular to the bead surface, indicating that the glass
was annealed. In contrast to the macroscopic appearance of the material, the inclusion patterns
seen under magnification are completely different
from the aggregates of small blue, white, and frequently metallic yellow grains commoi~lyseen inlapis lazuli. In figure 3, shallow depressions on thespherically molded glass can be recognized, and arein part filled with a white, grainy material that
evidently had never melted. However, true bubbles or swirls were not detected, although the glass
was observed with the microscope to be fairly
transparent around the white inclusions. The inclusions themselves ranged in size from a few
micrometers for the tiny white grains that form
the two types of aggregates to approximately 3 minfor the longest septa and several milliineters forthe ferns.
CHEMICAL AND X-RAY
DIFFRACTION DATA
According to Bannister's diagram for conventional
glasses (Webster, 1975, p. 3861, a calciuin or even aborosilicate glass could account for the refractive
index and specific gravity determined, but no reference to this particular lapis-imitation glass wasfound in the gemological literature (Crowningshield, 1974; Farn, 1977; Schiffmann, 1976;
Webster, 1975; and footnote below*; although- -aV/esf German color chaff sysfemon fhe bask of C.I.E. ~lluminanls.

290 nm to 320 nm (also the result of trace amountsof Fe], It must be stressed that the peak positions
and intensities visually observed with the spectroscope partially deviate from the recorded spectrometer data provided in figure 1. With the spectroscope, the bands were seen to be centered at about
660 nm (strong), 585 nm (medium, narrow), and
530 nm (inedium strong, very wide, asymmetric].

Notes and N e w T e c h ~ ~ i q ~ ~ e s

- --

-

*A very olcl, if
not the oldest, artificiallapis-like materialdates
back to pre-Christian times, when Egyptians sintered calcite,quortz, malachite, a n d azuri!e to create a brilliant blue substunce that is n o w called "Egyptian b l ~ ~ eI.n" ancient Egypt
this ~ n a t e r i awaslused{or scarabs, to ornament royal tolnbs,
and, i n powdered forn~,as a pigtnent and cosn~etic,The chemical co~npositionof "Egyptian blue" is close to, and its cryst(11line structure identical with, the mineral cuprorivaite, CaCu
[Si40jo] (G. Bayer, pcrsonal communication). The prodz1ctionof this material was made particularly sz~ccessfulthrough theless Ca a n d Cu, but
application of lead oxide or all<alifluxes. If
more all~alis,were used, a well-melted transparent-to-o~~aqueglass (colored b y Cu alone, or b y Cu, Co, and FE) would result(Bayer and Wiedem(lnn, 1976).

GEMS & GEMOLOGY

Winter 1983

229

Figure 2. W h i t e bands and radiating septa of
low-cristobalite i n a devitrified, opaque cobaltglass bead imitatinglapis lazuli. Section throughbead i n reflected light; magnified 6 x (Wild
M8/MPS55).

Nassau, (19801, reported a pyrite-lapis imitation
made of another blue specialty glass that contains
copper crystals, similar to a "goldstone"]. Chemical data, nowadays readily available throughnondestructive energy-dispersive X-ray fluorescence (XRF-EDS;Stern and Hanni, 1982),were certainly of interest in this case. Figure 4 exhibits nofewer than eight metallic element signals in addition to the strong silicon peak. When the AgL
series produced by the silver tube radiation was

Figure 3. Dendritic and radiating patterns of
w h i t e low-cristobalite exsolutions and essentially transparent blue areas i n a cobalt-glass
bead imitating lapis lazuli. Reflected light, magnified 13 x (Wild M8/MPS55).

successfully masked by a filter, the intensity of theSi peak was greatly reduced and an additional peak
due to potassium was resolved, providing for theidentification of at least nine metal oxides ad-

COUNTS

Figure 4. Unfiltered energy
spectrum of a specialty cobalt
glass imitating lapis lazuli;
counting t i m e 249 seconds(Tracor Northern 1 710 X-ray
Fluorescence Spectrometer).

Notes and New Techniques

249 SEC

ENERGY (KEU)

BL GLFISS,21-.02 K2 MOF,1/10/82
GEOCHEH. LRB/UNIU. BSL

GEMS & GEMOLOGY

Winter 1983

mixed to the Si02glass. Although boron cannot be
detected by XRF-EDS analysis, the fact that thebeads examined had a Mohs hardness of less than 6(which is low for a borosilicate glass] would suggest that boron is not present in this material insignificant amounts.
X-ray diffraction (XRD)provided the net identification of alpha-cristobalite. The X-ray film
showed 12 sharp lines in appropriate identifying
positions and relative intensities (JCPDSPowder
Diffraction Data, 1974). The four strongest lines(with their estimated intensities indicated in parentheses) were at 4.05 A (loo),3.14 A (10),2.84A[lo],and 2.48 A (20).Cristobalite is the only crystalline phase found in the glass. The mineralogicalliterature (Deer et al., 1975, etc.) describes naturalalpha-cristobalite as t h e metastable lowtemperature polymorph of SiO%with a tetragonal(pseudocubic) structure, a specific gravity of
2.32-2.36, and refractive indices of 1.484 (e) and1.489 ( 0 ) . Low-cristobalite is known to exsolvefrom certain glass types through a devitrification
process. The degree of order in the low-cristobalite
lattice depends on its thermal genesis.

REFERENCES

f

Bayer G., Wiedemann H.G. (1976) AgYptisch Blau, ein synthetisches Farbpigment des Altertums, wissenschaftlich
betrachtet. S d o z Bulletin, No. 40, pp. 20-39.
Biesalski E. (1957) Pflanzenfurben-Atlas. MusterschmidtVerlag, Gottingen.
Crowningshield R. (19741Imitation lapis lazuli: developments
and highlights at CIA'S lab in New York. Gems is) Gemology, Vol. 14, No. 11, pp. 327-330.
Deer W.A., Howie R.A., Zussman M.A. (19751 Rock-forming
Minerals, Vol. 4, Longman, London.
Farn A.E. (1977) Notes from the laboratory. Journal of Gemmology, Vol. 15, No. 7, pp. 358-372.

Notes and New Techniques

CONCLUSION
The cobalt glass described in this article is the bestglass imitation of lapis lazuli that this author has
seen to date (see also Webster, 1975, p. 221). Although lapis lazuli was immediately eliminated asa possible identification, the results of the investigation were unexpected because:

Glasses are not generally associated with
opaque solids.
The macroscopic appearance of the glass was
confusing.
No bubbles or swirls could be detected in thematerial studied.
The most diagnostic gemological property (considered along with the refractive index and specificgravity appropriate to a glass) is represented bycristobalite exsolution patterns seen under slightmagnification. In this instance, the identification
was secured beyond any doubt by the advanced
techniques of speetrophotometry, XRF-EDS, and
X-ray diffraction.

Hobbs J.M. (1982) The jade enigma. Gems ml Gemology, Vol.
18, NO. 1, pp. 3- 19.
Joint Committee on Powder Diffraction Standards (19741 Selected Powder Diffraction Data of Minerals, No. 11-695.
JCPDS, Swarthmore, PA.
Schiffmann C.A. (1976) Conlparative gemmological study oflapis lazuli and of its new substitute. Journal of Gemmology, Vol. 15, No. 4, pp. 172-179.
Stalder H.A. (1967) Blauquarz vom Taminser Calanda. Urner
Mineralicn-Frcunde, No. 5, pp. 1- 16.
Stern W.B., Hiinni H A . (19821 Energy-dispersive X-ray spectrometry: a non-destructive tool in gemmology. Journal ofGemmology, Vol. 18, No. 4, pp. 285-296.
Webster R. (1975)Gems. Butterworths, London.

GEMS & GEMOLOGY

Winter 1983

231

EDITOR
Chuck Fryer
GIA, Santa Monica

LAB NOTESCONTRIBUTING EDITORS
Robert CrowningshieldGem Trade Laboratory, New York
Karin N. Hurwit
Gem Trade Laboratory, Santa Monica
Robert E. Kane
Gem Trade Laboratory, Los Angeles

CORUNDUM, More on
Heat Treatment
We have been told that conservative
gem traders in Sri Lanka have beenreluctant to start heat treating theirown "geuda" corundum, fearful ofthe impact this would have on themarket for blue and yellow sapphires
mined on the island. However, theheat treatment activities of Thai operators using the "geuda" have already placed the Sri Lankans in competition with themselves for thesecolored sapphires. A new gas ovenfrom Japan that can be used with either a reducing flame (for blue sapphires) or an oxidizing flame (for rubies and yellow/orange sapphires)
could encourage heat treatment of
corundum in Sri Lanlza.
Although heat treatment is virtually undetectable in some corundum, occasionally we see a stonethat shows obvious signs of treatment. The New York laboratory
recently examined an unusual sapphire cabochon that was approximately 90% colorless and had a thinband of dark blue color on its base(figure 11. The fact that the stone fluoresced chalky green in bands when
exposed to short-wave ultraviolet
radiation, and that the base exhibited"heat" craters with no "bleeding"(figure 2), indicates that the stone
was heat treated rather than diffusion treated. Figure 2 also shows theeven appearance of the color whenviewed face up.
A 2.55-ct natural ruby of excellent color that was recently offered at
07984 Gemological Institute of America

232

Gem Trade Lab Notes

Figure 1. A thin band of blue o n
a n otherwise colorless sapphire.
Magnified 12 X.

I
Figure 2. T h e craters i n thebase of t h e sapphire s h o w n i nfigure 1 prove that this stone
w a s heat treated rather thandiff~rsiontreated. Magnified 12 X.

auction also showed unmistakablesigns of heat treatment. Unfortunately, the treatment caused severeinternal fracturing, and one wholeside of the pavilion (including theculet) had chipped away (figure 3).
The stone looked pleasant enoughtable up, but could not standscrutiny.

specific gravity was determined byhydrostatic weighing to be 5.52 forthe green stone and 5.34 for the bluestone. Both stones were inert to ultraviolet radiation. With the micro-'C-Ox," Another Trade Name
for Cubic Zirconia

Figure 3. Note t h e internalfrac~uringand external chippingon this 2.55-ct ruby, caused b yheat treatment. Magnified 16 x.

The Los Angeles laboratory received
for examination two colored stones
that had been offered on the European market under the trade name
"C-Ox." Figure 4 shows the deep
green emerald-cut stone, whichweighed approximately 4.14 ct, andthe intense blue oval modified brilliant, which weighed approximately
3.73 ct. Both stones had a very high,almost metallic luster; both were
singly refractive, and their refractive
indices were above the limit of ourstandard duplex refractometer. The

GEMS & GEMOLOGY

Winter 1983

sions in diamonds several times
before (Gems a ) Gemology, Winter
1965-66, Fall 1966, Fall 1974, Fall
1979, and Spring 19801, we havenever seen anything that equals theone in the approximately 4-ct stone
pictured in figure 8. Viewed from thepavilion, the major inclusion looks
like a branching root system. However, because of its location within
the diamond and the fact that thestone is pear shaped, the odd patternis reflected throughout the entire
stone (figure 9).
Figure 4. Green (4.14 ct) and blue (3.73 ct) cubic zirconia, marketed
under the trade name "C-Ox."

JADE Simulant

with fancy yellow to yellow-brown
diamonds pictured in figure 6. The
small stars are mounted entren~blantand are interspersed with

A small (3 cm diameter), round ornament carved out of an opaque, yellowish brown, black, and grayish
green material was submitted to the
Santa Monica laboratory for identifi-

Figure 6. Comet-design
diamond brooch set withcolored diamonds. Approximutely 3 %in. (9 cm).

Figure 7. All of thestones in thebrooch illustrated in figure 6
fluoresce when exposed tolong-wave U. V. radiation.

small colorless diamonds. The pieceis unusual in that all of the stones,
including the small colorless ones,
are fluorescent, which suggests that
whoever designed the piece andchose the stones had more than apassing interest in diamond fluorescence. Figure 7 shows the brooch as it
appears when exposed to long-wave
ultraviolet radiation.

Figure 8. Dendrites indiamond. Magnified 12 x.

Figure 5. Absorption spectrum of
the green "C-Ox" illustrated infigure 4. 'scope, no inclusions were visible inthe blue stone, but the green stone
showed a dense cloud of minutewhite inclusions that we could not
identify. The absorption spectra of
the stones were interesting. The bluestone showed a general absorption
area around 5900 A and a cut-off area
starting at 6500 A upwards. The
green stone had a different absorption pattern: one broad, main absorption area was centered at 4450 A,
with narrower bands at 4700, 4800,
5800, and 6000 A and a cut-off areafrom 6500 A up, as illustrated in figure 5. By means of X-ray diffraction,
we were able to prove that bothstones were synthetic cubic zirconia.

DIAMOND
A Colored-Diamond Comet
The New York laboratory recently
examined the diamond brooch set

Gem Trade Lab Notes

Dendri tic Inclusions
Although we at the New York lab
have encountered dendritic inclu-

GEMS & GEMOLOGY

Winter 1983

233

refractive index of the light green
material indicated maw-sit-sit,
while preliminary tests on the darkgreen material indicated chloromelanite. If additional tests areauthorized and confirm these identifications, it would be the first example of this combination ever encountered in our lab.
OPAL, A New Synthetic
from Inamori

Figure 9. The pin containing the approximately 4-ct diamond
illustrated in figure 8 with the dendrite pattern reflected throughout
the stone.

MAW-SIT-SIT?

Our New York laboratory recently
examined a sawed light-green boulder that weighed approximately
eight pounds (figure 11). On thereverse side of the rock a typical
mawed groove has exposed a darkgreen area that resembles chloromelanite. The specific gravity and

Figure 10. Ornament composed
primarily of serpentine as a jadesimulant.

A new type of synthetic white opal
manufactured by Inamori has appeared on the American market. The
Santa Monica laboratory had the opportunity to examine two 10 x 12mm cabochons, each weighing approximately 2.80 ct (figure 12). One
cabochon has a milky white bodycolor with predominantly green andblue play of color, while the otherstone is more translucent, with avivid play of color in red, orange, yellow, green, and blue. The refractive
index was determined to be 1.46
(spot reading) for both stones, and thespecific gravity for both was 2.20.
Examination with magnification did
not reveal any distinctive inclusions
in the more translucent stone; theFigure 11. An eight-pound boulder that appears to consist of
maw-sit-sit and chloromelanite.

cation (figure 10).The material wasvery soft and could be scratched witha pin. Although the polish was not
good, we were able to obtain a vague
refractive index reading of 1.57 insome areas. The specific gravity wasdetermined by hydrostaticweighing
to be approximately 2.5. There was a
distinct yellow fluorescence to both
long- and short-wave ultraviolet radiation. X-ray diffraction revealed
patterns of forsterite and antigorite
as well as additional lines thatproved the material was a rock consisting of several minerals, but
primarily serpentine.

234

Gem Trade Lab Notes

GEMS & GEMOLOGY

Winter 1983

(figure 13).The X-radiograph (figure14) shows a considerable growth ofnacre around the beads. The verythin layer of shell to which the beads
were attached does not appear on theradiograph.

Figure 12. Two 10 x 12 mm Inamori synthetic opals.

Eroded Pearl
A pearl importer thought our readers
would be interested in seeing a badly
damaged pearl that he had beenasked to replace [figure 15).It was set
in a ring with a typical claw mounting when he received it. After unmounting the pearl, he sent it to the
Santa Monica laboratory to photograph the severe erosion at the pointsof contact of the prongs. We surmisethat the person who wore this ringmust have worn it a lone time andhad a very acidic skin condition, for-milky white stone did show an
opaque white, irregularly shaped inclusion that.could not be identified.
When the stones were illuminated with overhead light, the lizard
skin or chickenwire structure characteristic of synthetic opals, which
was difficult to detect at first, became quite obvious. Finally, the twostones reacted differently to ultraviolet radiation. The milky white stone
was completely inert, whereas theother stone showed a faint yellowish
fluorescence, but only to short-wave
ultraviolet radiation.
Figure 13. Cultured % blister pearls without exposed nuclei. The
largest is 21 x 18 inm.
PEARLS
Cultured % Blister Pearls
In the Summer 1981 issue of Gems dGemology (p. 104), we introduced
cultured % blister pearls. To date, allof the examples of this new type of
pearl that we have seen have had amother-of-pearl bead clearly exposedat the base. Recently, the New Yorklab X-rayed two 18-mm cultured Â¥'/blister pearls in which the nuclei
were not exposed. The pearls had
been removed from the mollusc withshell attached. The nucleus of thesmaller specimen was just visible-a
white area underlying the thin shell

Gem Trade Lab Notes

Figure 15. Eroded 8Vz-mm
pearl.
Figure 14. X-radiograph of thecultured % blister pearls shownin figure 13.

GEMS & GEMOLOGY

Winter 1983

235

this is one of the worst examples of
erosion we have ever seen.

QUARTZ, Reddish Brown

Submitted to the Los Angeles laboratory for identification was the
4.72-ct reddish brown oval modified
brilliant shown in figure 16. The
refractometer showed refractive indices of (D = 1,540 and e = 1.550.
When the stone was examined withthe polariscope in conjunction with acondensing lens, a bull's-eye uniaxial interference figure was observed, thereby proving the stone to
be auartz.
This color has been observed insome quartz from Rio Grande do Sul,
Brazil, and is also reportedly produced by heat treating some amethyst to a temperature between
400Â° and 500Â°C
Microscopic examination revealed only straight, parallel, and irregular growth and color zoning,which suggests that this stone isnatural rather than synthetic. This
color, however, could probably be
produced in synthetic quartz, or byheat treating synthetic amethyst.

Figure 17. A 1.46-ct "Geneva(synthetic) Ruby," heavily
flawed.

Figure 19. A range of colors found i n heat-treated yellow sapphires.

Figure 20. "Cotton-like"inclusions observed i n heat treated yellow sapphires.
Magnified 63 X.

Figure 16. Reddish brownquartz, 4.72 ct.

RUBY, Early Verneuil Synthetic
Figure 17, taken in New York, showsan unusually flawed 1.46-ct "Geneva
Ruby." The tight curved striae thatcharacterize this early type of Verneuil synthetic were easily seen in
the stone with magnification. In addition to the striae and gas bubbles,236

Gem Trade Lab Notes

Figure 18. Note the dark
inclusions i n the "Geneva(synthetic) Ruby" illustrated i nfigure 17. Magnified 18 X.

we observed a myriad of unidentified
dark crystal-appearing inclusions(figure 18).

YELLOW SAPPHIRES,
Heat Treated
Recently, the great majority of natu-

ral yellow sapphires we have tested
in New York owe their color to heat
treatment. On rare occasions, wehave seen an orange-brown iron-richstone of natural color, but more frequently the naturally colored stones
are pale yellow with strong orange
fluorescence. Figure 19 illustrates arange of colors produced by heat
treatment; the stones are all from thesame batch heated in Thailand. Figure 20 shows some peculiar "cottonlike" inclusions around the crystal
inclusions seen in one of the lightercolored stones. The "cotton" mayrepresent partial absorption of thecrystal inclusions because of heat.
Figure 21 shows a group of natural sapphires that reportedly had
been locked in a safe for decades. It
was a pleasure to be able to reportthat the stones were not only natural
sapphires but also natural in color,although they were quite well worn.
The square, lighter-colored stone is atypically orange-fluorescing Sri
Lanlzan stone. The oval stone next to

GEMS & GEMOLOGY

Winter 1983

Figure21. Agroup of naturally colored yellow sapphires. Thelargestis
approximately 4 ct.

it is also a typical Sri Lankan stone,
with a chromium line in the absorption spectrum. The small orangepink stone was nearly flawless, but
proved to be natural. The roundstone again had all the characteristics of a darker than usual Sri Lanlzanstone, while the dark stone showed
an iron absorption spectrum typicalof natural* yellow-brown Thai
sapphires. ':ZIRCON, A Rare
Cat's-Eye
The Santa Monica laboratory re-

Gem Trade Lab Notes

ceived for identification a grayish
green3.43-ct oval cat's-eye cabochon
that had been purchased as cat's-eye
zircon. The stone was easily identified as zircon because it showed the
diagnostic absorption spectrum withthe most prominent line at 6535 A.
Microscopic examination revealed
long, thin, needle-like inclusions of
unlznown composition running
across the stone, thus causing thechatoyancy. Figure 22 shows thequite attractive cabochon. Although
cat's-eye zircon does not-according
to the gemological literature-occur
often, our New York laboratory had
previously mentioned this type of

Figure 22. A 3.43-ct cat's-eye
zircon.
cat's-eye in the Summer 1974 issueof Gems d Gemology.
ACKNOWLEDGMENTS
Andrew Quinlan from New York suppliedfigures1,2,3,6,7,8,9,11,13,14,17.18,
19, 20, and 21. Shane McClure provided
figure 16. Figure 22 was supplied by Tino
Hammid, and Karin Hurwit was responsible
for figures 5 and 10.Mike Havstadsuppliedfigures 4, 12, and 15.

GEMS & GEMOLOGY

Winter 1983

237

GEMOLOGICAL ABSTRACTS
Dona M.Dirlam, Editor
REVIEW BOARD
Stephanie L. Dillon
San Clemente, California
Bob F. Effler
GIA, Santa Monica
Joseph 0. Gill
Gill & Shortell Ltd., San Francisco
Fred L. Gray
Richter's, Nashville
Mahinda Gunawardene
Idar-Oberstein, Germany

Gary S. Hill
GIA, Santa Monica
Steve C . Hofer
ken sing tor^, Connecticut
Karin N. Hurwit
Gem Trade Lab, Inc., Los Angeles
Neil Letson
Anniston, Alabama
Shane F. McClure
Gem Trade Lab., Inc., Los Angeles
Michael P. RoachAndin International, New YorkCOLORED STONES AND
ORGANIC MATERIAL
Crystal chemistry of natural Be-Mg-A1oxides: taaffeite,
taprobanite, musgravite. K. Schmetzer, Neues
fahrbuch fiir Mineralogie Abhandlungen, Vol. 146,
No. 1, 1983, pp. 15-28.
Schmetzer describes the Be-Mg-A1 oxides taaffeite andmusgravite, and the controversy centered on the discredited term taprobanite. Although similar, taaffeite
and musgravite have slight differences in their chemistry and crystal structure, and the present investigation
was undertaken to clarify their complex interrelationship. Chemical, crystallographic, and optical data
are given for 15 specimens from Sri Lanka, China, theSoviet Union, and Antarctica. Optical absorption specThis section is designed to provide as complete a record as
possible of the recent literature on gems and gemology. Articles
are selected for abstracting solely at the discretion of the section
editor and her reviewers, and space limitations may require that
we include only those articles that will be of greatest interest to ourreadership.
Inquiries for reprints of articles abstracted must be addressed tothe author or publisher of the original material.
The reviewer of each article is identified by his or her initials at theend of each abstract. Guest reviewers are identified by their fullnames.
01984 Gemological Institute of America

238

Gemological Abstracts

Gary A. Roskin
Gem Trade Lab, Inc., Los Angeles
James E. Shigley
GIA, Santa Monica
Frances Smith
GIA, Santa Monica
Carol M. Stockton
GIA, Santa Monica
Evelyn Tucker
Anchorage, Alaska
Jill M. Walker
GIA, Santa Monica

tra are also presented for a bluish-violet taaffeite from Sri
Lanka. Taprobanite, originally thought to be a new species, is shown to be identical with taaffeite, whose correct chemical formula is BeMfaAlaO16. The speciesname taaffeite has priority according to the rules ofmineralogical nomenclature; the name taprobanite
should be discontinued. Musgravite has a similar composition of BeMg2A16012,but it has not yet been foundas gem-quality crystals.
fEs

Editor's Note: Schmetzer expands on the subject of nomenclature in his article "Taaffeiteor Taprobanite-a
Problem of Mineralogical Nomenclature" i n the Vol.
18, No. 7 issue of Journal of Gemmology, pp. 623 -634.
Color pictures of nine taaffeites are included.
Durchsichtieer- Lazulith oder Scorzalith aus Brasilien(Transparentlazulite and scorzalite from Brazil). H.
Bank, Zeitschrift der Deutschen Gemmologischen
Gesellschaft, Vol. 32, No. 1, 1983, pp. 6-9.
Currently a blue transparent to translucent gemstone isbeing sold in Brazil under the name scorzalite. Professor
Bank has suggested mineralogical and gemologicalmethods to determine the members of the isomorphousseries lazulite-scorzalite. The mineralogical methods
include the use of X-ray powder diffraction patterns andthe microprobe. Refractive index, birefringence, anddensity determinations are the gemological methods.
The Mg-rich end member lazulite and the Fe-rich
end member scorzalite provide lower and higher physi-

GEMS & GEMOLOGY

Winter 1983

cal constants, respectively. The values given in this article for lazulite are n,, 1.608-1.610, n, 1.640-1.644,
nz-nx 0.032-0.034; and for scorzalite, nv 1.639, n,
1.680, n,-nx 0.041. The density of lazulite varies
from 3.06 to 3.12; density is quite constant at 3.31 forscorzalite.
This information enables the gemologist to identify
the intermediate members of the series. Analyses havealso concluded that the material offered as scorzalite
from Brazil is actually lazulite.

Mahinda Gunawardene
On tourmaline. T. G. Sahama, 0 . von Knorring, and R.
Tornroos, Lithos, Vol. 12, 1979, pp. 109-114.
Tourmaline is a closely related group of minerals ofparticular gemologic interest. This brief article presents
chemical analyses and physical properties of 12 tourmaline specimens of varying color-10 from Mozambique, one from Afghanistan, and one from the Malagasy
Republic. The material from the Muiane district inMozambique exhibits a range of hues from colorless
achroite to black schorl. The specimen from an unknown pegmatite locality in Afghanistan is blue, while
the one from the Malagasy Republic (from the Itakefa
Mine near Fort Dauphin) is dark brown. These reported
data are ofinterest because, in view of the complexity ofthis mineral group, sources of information on tourmaline t h a t include complete chemical compositions andphysical properties obtained from the same crystal arescarce. A short discussion of the relationship between
chemical composition and unit-cell parameters is alsopresented.
IES
Pearlescence. A. DiNoto, Connoisseur, Vol. 213, No.
858, 1983, pp. 76-87.
This is a lavish update of all the nontechnical information you have ever read or heard about pearls, with theadded feature of truly informative footnotes. The author
cites well-respected authorities (including G. F. Kunz
and GIA), explores the myths and legends about pearls,
reviews market fluctuations related to fashion trends
and economic conditions, examines the varieties of
pearls being found or produced today, and discusses thewide range of current prices, which reflect both quality
and scarcity.
Comments from leading dealers, importers, andauction-house authorities provide ample evidence of aflourishing market and reveal astonishing new sourcesof supply.
While the photographs display an interesting varietyof antique and contemporary pearl jewelry, there seems
to have been some uncertainty about new and imaginative ways to illustrate pearls to their best advantage.
Unfortunately, neither this article nor any other manages to do so with complete success since, unlike someother types of jewelry, pearls seldom appear as beautiful
in photographs as they do in reality.
NL

Gemological Abstracts

The thermal behavior of scapolites. G. Graziani and S.
Lucchesi, American Mineralogist, Vol. 67, No.
11/12, 1982, pp. 1229-1241.
Graziani and Lucchesi report results from thermalexpansion experiments conducted on scapolites fromdifferent localities. They measured the release of volatile components during heating of these samples over an
800Â° temperature range, They specifically chose samples that represented the marialite-meionite solidsolution series.
Of the eight specimens, a violet and a yellow camefrom the Umba deposits, northeast Tanzania; two werefrom Ankazob6 and Gabenja, Madagascar; onewas from
Gooderham, Ontario, and another was from Greenville,
Quebec, in Canada; one came from Manchester, New
Hampshire; the last originated from the Mt. Somma-Mt. Vesuvius area in Italy.
While much of the data are outside the interest of
most gemologists, it is important to note that water loss
begins to occur at temperatures as low as 70Â°CAlso, theauthors report a progressive lightening of the color withheating until 350-400Â°C when the samples becamecolorless. An extensive bibliography of 40 entries is
included.
DM D
Wyoming jade. M. E. Madson, Rocks and Minerals, Vol.
58, No. 5, 1983, pp. 218-222.
Madson reviews the history of Wyoming nephrite before
turning to a discussion of its mineralogy and petrology.
One very early account of its use as a lapidary material
was in 1908. Harvey Samuelson of Salinas, California,bought green nephrite from Wyoming cowboys who
were wintering in California. Later, in 1936, a "jaderush" began that lasted for 10 years. This prospecting
was accelerated by the widening acceptance of Wyoming nephrite as a lapidary material. By the mid-1950s,
the major deposits had been claimed. Most recent production comes from these deoosits.
Occasionally, however, deposits that were previously known but only lightly worked have come into
prominence. Madson was involved in a major mining
effort from 1971 to 1975 on the Rhoades deposit in theGranite Mountains northwest of Jeffrey City, Wyoming.
He states that the mine produced 400,000 pounds ofnephrite; about 6% was gem quality. This material wassent to Taiwan and Germany for manufacture.
He also reports findings from his investigation of themineralogy of Wyoming nephrites. These nephrites areintermediate in chemical composition between tremolite and ferro-actinolite; most of the gem-quality material is tremolite. He also reviews nephrite competency (acombination of strength and hardness) and the color
range exhibited in nephrites from different regions.
Then, the author describes the three modes of occurrence of Wyoming nephrite: (1)float, (2)vein and fissure
fillings, and (3)ellipsoidal pods.

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Winter 1983

239

Noting that more and more often light-colored nep h r i t e ~from British Columbia are being sold in Wyomine, Madson concludes that 1935-1975 may well represent the prime period of the nephrite industry in
Wyoming.
DMD

DIAMONDS
Argyle diamond mines' operational debut. Indiaquu,Vol. 34, No. 1, 1983, pp. 13-23.
In a series of reprints of newspaper articles, Indiaqua
chronicles the history of the Australian diamond deposits. It begins with a December 28, 1982, story fromthe S y d n e y Morning Herald announcing an agreement
between two of the Argyle partners, CRA Ltd. andAshton Mining Ltd., and the De Beers Central Selling
Organization. This sales pact with De Beers is unique inthat there are several provisions that allow somedomestic cutting and marketing by the joint-venture
partners,
The other articles are arranged in reverse chronological order, and present issues relevant to the Western
Australian state government and De Beers. With somany people affected by these large finds of diamonds(up to five tons annually, most of which are of industrial
or low-grade gem quality), it is interesting to read in asingle format the stories of each participant. Particularly
noteworthy is the article from 1976 reporting the initial
diamond find.
One difficulty for the reader is that some of the articles are not dated. Thirty photographs illustrating thesedevelopments accompany the text.
FLG
Argyle's high grade. M i n i n g Journal, Vol. 301, No. 773 1,
October 21, 1983, pp. 291-292.
This is a short update on diamond-mining events inAustralia. During the week of October 14, 1983, agreement was reached between the Western AustralianGovernment and the partners of the Argyle Diamond
Mines Joint Venture to develop the AK-1 kimberlite
pipe. On November 1, 1983, construction was scheduled
to begin on a treatment plant that will be capable ofrecovering 25 million carats of diamonds from three
million tons of ore annually. It is expected that production will begin by January 1,1986. Since most diamonds
will be industrial or low-grade gem, it is expected thatthey will comprise 4% of the value of the worldwide
production. The weight estimates for the AK 1 are predicted to be 5% gem quality, 40% cheap gem, and 55%
industrial grade. In addition to summarizing information on ore grades and production figures from the 1983
annual report of Ashton Mining Ltd., this article also
includes an outline map and simplified cross sections of
the deposit.
DMD

240

Gemological Abstracts

Diamond-bearing kimberlite pipes in Wyoming andColorado. W. D. Hausel, Rocks a n d Minerals, Vol.
58, NO. 5, 1983, pp. 241-244.
Hausel's account is an intriguing tale of geological investigation that led, ultimately, to the discovery of diamonds. The problem began in 1960 when geologists
discovered blocks of Lower Paleozoic limestone(450-500 1n.y.) in southeastern Wyoming. No rocks ofsimilar age occur close by. Furthermore, these outcrops
are in the middle of Precambrian granite dated at 1.4 b.y.
The mystery continued until 1964 when similar limestone was discovered in Colorado. This time, kimberlite
was found in association. The geologists concluded thatwhen the kimberlite magma erupted 350 to 400 m.y.
ago, Lower Paleozoic limestone covered the area. Since
then, erosion has removed all traces except for thesechunks trapped in the erupting magma.
Diamonds were not discovered until 1975. During
grinding, a nodule from one of the kimberlite pipes
scratched the Carborundum wheel. With further treatment, the geologists found diamonds 0.1 to 1.0 mm in
the residue. Geologists from the Geological Survey of
Wyoming and Colorado State University combined t o
explore the region. Now, nearly 100 kimberlite occurrences have been located; more than 12 of these are
diamond bearing.
Two mining firms, Cominco America, Inc., and Superior Minerals Company, are investigating the commercial diamond potential of the Colorado-Wyoming
region. The Geological Survey of Wyoming continues totest kimberlites for diamonds. Although Hausel includes two photographs of diamonds and one crosssection of a Wyoming diatreme, the map of the kimberlite localities and the bibliography are the most usefulsupplements to the text.
DMD
Diamonds, diggers and dreams. D, E.Schaefer, Optima.
Vol. 31, No. 2, 1983, pp, 74-90,"Diamonds, Diggers and Dreams" is a historical yet
colorful account of the hopes and dreams that sent
gamblers to the South African diamond fields. This lookback a t the early days of diamond mining restricts itself
to a very brief moment in history in the late 1800s,
making one feel part of the excitement, hard work, losthopes, and fulfilled dreams of the men and women who
gambled with their lives to find those elusive
crystals-diamonds. "Of course I thought that once on
the field every load a stone would yield; But, I owned,
after many a weary day, that gravel is gravel and clay isclay. Itreally wasvery unpleasant. But i t can't be helped,
you know."
As one can already feel from this brief lament, "Diamonds, Diggers and Dreams" is much more enjoyable
reading than a standard history text on the early days of
diamond mining. We view these times through wonderful photographs, poetry, and other writings from the

GEMS & GEMOLOGY

Winter 1983

men and women who were there. This helps remind us
how sought-after and precious these adamantine crystals of colorless carbon really are. "I havea wife, a claim I
mean, a baby and a cradle too, which I constantly workfrom daylight till dark in search of a diamond or two."Yes, those were exciting times, the early days of diamond mining. And this reading makes you wish you
could have been there. "Hurrah! for the diamond fields!
With its stores of wealth untold. Hurrah! for the rich andsparkling gems to win u s piles of gold."
GAR
Diamonds in the People's Republic of China, part I andpart 11. B. Hawkins, D i m n t , Vol. 26, No. 267,
1983, pp. 29-30; NO. 268, 1983, pp. 25-32.
In part I, Hawkins summarizes the longer version presented in part 11, which begins with a description ofChina's diamond deposits. The only confirmed mine iscalled Changte, after the nearby town in the northernpart of Hunan province. A geographic outline map of thePeople's Republic of China allows one to locate Changte
as well as the other deposits reviewed. These latter locations have been derived from reports of discoveries ofindividual diamonds since the government is reticent totalk about the diamond localities.
In a short section on diamond production, Hawkins
reports a n o u t p u t for 1980 of 1.8 to 2.8 million carats,
with about'20% of the diamonds ranked as gem quality.
In the next two sections, Hawkins focuses on the diamond trade and the cutting industry. He speculates thatthe exported cut stones go to the United Kingdom andWest Germany. In a brief note on synthetic diamonds,
he reports that the first synthetic grit was produced in
China in 1963, and by 1980 six synthetic production
units were in operation, allowing a significant reductionin China's importation of industrial diamonds.
Hawkins concludes with a prediction of a gradualincrease in both natural and synthetic diamond production, although one not large enough to make China asignificant diamond leader. In an interesting appendix
entitled "Diamonds: China's Connections with De
Beers," instances of contact between the two since 1975
are cited.
DMD
Digging for diamonds. P. Read, Canadian Jeweller, Vol.
104, NO. 5, 1983, pp. 28-32.
Read reports on his November 1982 trip to the Finsch
diamond mine, located 160 k m northwest of Kimberley,South Africa. He begins by summarizing the discoveryof the mine by Allister Fincham and Ernest Schwabel. In
the 1950s, while prospecting for sources of asbestos,they discovered garnets. Realizing that this occurrence
also suggested diamonds, they started to search for kimberlite. By November 1961, they began to remove overburden from a likely area. A 0.75-ct diamond was foundin the first washing of gravel. By May 1963, output of
diamonds was up to 1,634.45 ct. That same month, theGemological Abstracts

two partners sold the rights of the Fincham mine to De
Beers Mining Company [Finsch is an amalgam of Fincham and Schwabell.
Today, the ~ i n s c hmine, now covering an area of 44.2
acres, is the second largest diamond mine in South Africa. Read also describes in detail the current efforts toconvert the mine from an open-cast to an underground
operation. This project is expected to be completed by
1988, with production estimated a t four million tons,
and more than three million carats of diamond, per year.
This article is followed by Read's one-page description of
the De Beers Diamond Research Laboratory, which celebrated its 36th-year anniversary i n 1983.
DMD
Famous diamonds of the world (XV): the "Hastings"
diamond. 1. Balfour, Indiaqua, Vol. 34, No. 1, 1983,
pp. 129-133.
As with many other large diamonds, the Hastings diamond has a history of intrigue and mystery. Ian Balfour,in another article from his series, "Famous Diamonds ofthe World1' has spun an interesting tale.
This 101-ct rough diamond received its name fromthe first British Governor General of India, Warren Hasti n g ~ Mr.
. Hastings was in attendance on the presentation of this diamond to King George 111 by the importantIndian prince, Nazam Ali Cawn. A story was then circulated that Mr. Hastings had sought to curry the king's
favor by helping him acquire this diamond. Once begun,
the scandal progressed under its own momentum. Twoyears later Mr. Hastings was fornlally impeached, andthe trial that followed lasted over seven years. Ultimately, Hastings was acquitted of all charges.
Although there is no proof, Mr. Balfour speculates
that the diamond became part of the British Crown
iewels and was cut into a 32.20-ct round brilliant andmounted into the coronation crown of George IV. Subsequently purchased at auction by the marquis ofWestminster, the Hastings diamond was then mounted
in the Westminster Tiara along with two other famous
diamonds, the Arcots. In 1959 Mr. Harry Winston purchased the tiara and later sold the stone to a private
FLG
collector.

GEM INSTRUMENTS
AND TECHNIQUESA spindle state study of the optical properties of topaz.
M. F. Carman, Jr., Bulletin d e M i n h l o g i e , Vol. 104,
1981, pp. 742-749.
The author has made very accurate measurements of the
optical properties of a topaz crystal of unknown origin
using a recently perfected microscopic technique. This
technique involves mounting a tiny crystal fragment on
a needle, or spindle, attached to a movable stage. T h efragment is then rotated into various positions for optical measurements under the microscope. Refractive indices using 589-nm light are Nx = 1.6109 (31, Ny =GEMS & GEMOLOGY

Winter 1983

241

1.6137 (3))and N, = 1.6209 (3). Data on other opticalproperties are also presented. The analyzed fluorine content (19.3-19.7%) determined by electron microprobe
agrees closely with the content calculated from thesemeasurements.
1ES

GEM LOCALITIES
Gem azurite from the Eclipse Mine, MuldivaChillagoe area, Queensland. A. D. Robertson, Australian Gemmologist, Vol. 15, No. 2, 1983, pp.
46-49.
From 1892 to 1927 silver was mined at Muldiva in
Queensland, Australia; gem-quality azurite crystals
were recovered from the Eclipse Mine in this area as
well. Economic mineralization at Muldiva was associated with contact skarn deposits developed in limestone. Extensive weathering of the garnetiferous slzarn
and subsequent oxidation of copper sulfides in theweathering zone produced large azurite crystal clusters;
the largest group weighed 0.9 kg, while the largest single
crystal weighed 8.75 gm.
The author has classified the azurite crystals into
three fundamental categories, based on the type of termination and the development of crystal faces. Physicalproperties of the azurite are described and include t h efollowing: step-like cleavage breaks partially obscured
by conchoidal fractures; strong pleochroism in blue;
specific gravity of 3.789 Â 0.003; absorption above approximately 480 n m and below approximately 430 nm.
Refractive indices were not determined. Some of thespecimens showed replacement by malachite while retaining the azurite crystal forms (pseudomorphism).
The various stages of replacement are noted i n detail.
In addition, the article includes a listing of 21 minerals found i n the Muldiva ores.
Robert C. Kommerling
Neues vom Smaragd-Vorkommenvon Sta. Terezinha de
Goids, Goids, Brasilien (New information from anemerald source in Sta. Terezinha in Goihs, Brazil).
H. A. Hanni and C. J. Kerez, Zeitschrift der
Deutschen Gem~nologischenGesellschaft, Vol. 32,
NO. 1, 1983, pp. 50-58.
The authors examined emerald crystals and rock samples from the new emerald mine i n Santa Terezinha,
Brazil. T h e hexagonal prismatic crystals are found intalc and in biotite schists. Color varied from light green
to dark green with a bluish overtone resembling emeralds found in Zambia. T h e R.I. ranged from 1.585- 1.587
to 1.592-1.595; birefringence was 0.006 to 0.008; S. G.
ranged from 2.752 to 2.764. The absorption spectrum
was the same as the spectrum encountered in emeraldsfrom Madagascar. T h e inclusions were examined byelectron microprobe and identified as dolomite and picotite, a chromian spinel. A quantitative chemical anal-

242

Gemological Abstracts

ysis on four crystals showedvolumepercentages that arecharacteristic of most natural emeralds. In the 12 color
photographs are examples of the inclusions, an assortment of rough stones, and two views of the mine.
IZNHJEWELRY ARTS
Archaic jades, ancient & modern. M. Gulbenlzian, Artsof Asia, Vol. 13, No. 3, 1983, pp. 97-105.
Mr. Gulbenkian provides a pictorial essay of jade invarious eras. H e divides his discussion of samples into
stages. The first six are the Neolithic, Shang, Western
Chou, Spring and Autumn, Warring States, and Han.
Next, Gulbenkian covers the Archaistic, Northern Wei,
Southern Tan, Sung, the 13th through 17th centuries,
Ming, and Manchu periods.
Gulbenlzian describes one or more pieces of jade ineach period. In most of these short descriptions, someattempt is made to give the historical significance ofeach piece. The author's purpose of writing the article
was to "give a clear idea of current fashions as well as thelinear development of the craft." Unfortunately, neither
theme is adequately developed.
Some of the pieces illustrated are: a pi of the Shang
period, a huang of white jade of the Western Chou period, a chape [tip of a scabbard) of the Warring States
period, a sword of the Han period, a belt buckle with afeline image from the Sung dynasty, and a curling monster carving from the Ming dynasty. The author also
providcs his own sketches of jade carvings from many ofthese periods.
IMw

Bracelets for bullets. V. Becker, House ell Garden, Vol.
155, No. 6, 1983, pp. 48-52.
Berlin iron jewelry became fashionable during the Napoleonic Wars of the late 18th and early 19th centuries; thefirst factory for the production of this type of ornament
opened in 1804 in Berlin. Less than a decade later appeals
were being made to the wealthy to surrender their jewels
for the Prussian national cause, with iron jewelry being
issued as a form of receipt. While its popularity grew outof the difficult time of war, Berlin iron jewelry did notdisappear when peace was restored and, passing throughvarious stylistic changes, survived until the 1860s.
The skill of its fabrication lay in the casting, and its
visual effect depended on the startling contrast of delicate, lacy black jewelry with white skin, since at thattime women did not seek the sun, and a soft, white
complexion was much admired.
In this article, the authorwrites more engagingly andinformatively than i n the section of her own book (Antique and 20th Century Jewellery, London: N.A.C.
Press, Ltd., 1980)which deals with this period of jewelry
history. However, the article does not mention Ann
Clifford's Cut Steel and Berlin Iron Jewellery (Bath:Adams & Dart, 1971), the definitive work on Berlin iron

GEMS & GEMOLOGY

Winter 1983

jewelry, and therefore does a slight disservice to readers
who might wish to pursue the subject beyond the limNL
itations of a short article.
Chinese jade books in the Chester Beatty collection. J.
Chapman, Arts of Asia, Vol. 13, No. 3, 1983, pp.
110-119.
Chapman, the Far East curator of the Charles Beatty
Library and Gallery of Oriental Art located in Dublin,
Ireland, presents another facet of this remarkable collection as he focuses on the 15 jade books. These are notbooks about jade; rather, they are books writtenon jade.
The practice dates back at least 2,000 years. An ancient
Chineseritual book, Li Ki,states that while bamboo was
the writing material used by commoners, jade wasstrictly reserved for the emperor. From the Ch'in dynasty (221-206 B.C.) on, two sets of jade tablets wereused in a ceremony called feng-shan which thanked theruling spirits and petitioned them to continue to preserve peace and prosperity. One set of tablets was buriedat the site of the altar while the other was taken to theancestral shrine of the emperor.
Horizontal holes were drilled in the too and bottomof each tablet. Then a cord was threaded through so thatthe books could be folded in concertina fashion. For
storage, special boxes were constructed to hold eachbook, which sometimes numbered as many as 53 tablets. Two of the books have Manchu script as well as
Chinese.
Of the'15 books in the Chester Beatty collection,
seven are imperial notes and poems, five are Buddhist
texts, and three are official records. Chapman summarizes the known history of the different books, as well as
details about how Beatty acquired them. Photographs ofeight of the 15 are included, five in color.
DMD
Dazzled by nature. G. Trotta, Connoisseur, Vol. 213,
NO. 859, 1983, pp. 86-89.
Brazilian Haroldo Burle Marx is the dazzled one. He in
turn dazzles the reader with his designs in gold and silver
alloy set with emeralds, aquamarines, tourmalines, topazes, opals, and other colored stones of Brazil, which
are worn by the rich and powerful around the world.
Marx, who has designed jewelry for Pope John Paul I
as well as for Happy Rockefeller, calls his workshop in
Rio de Janeiro "a team bound together more by love thanby business." The social and aesthetic philosophy that
informs his work is the subject of this interview which,despite Trotta's oddly patronizing tone, is informative
and thought-provoking. Dane Penland's five photographs and three of Marx's own drawings con~plement
the text and make one hunger for more.
FS
Precious platinum. J. M. Filstrup, Town &> Country, Vol.
137, NO. 5037, 1983, pp. 112-187.
Ms. Filstrup describes the wide range of uses for plati-Gemological Abstracts

num, as well as its history and its alluring qualities infamous jewelry pieces.
Platinum is an invaluable metal in many fields oftechnology, from space exploration to chemotherapy
treatments. Because of its rarity, the majority of the U.S.
supply is used for industrial purposes.
In jewelry, platinum is becoming a more popularsetting material, due in part to the renewed interest in
Art Deco. Certain stones seem to be more aestheticallypleasing than others when set in platinum; some examples given by the author are aquamarines, amethysts,
tourmalines, and diamonds.
The author also discusses the investment possibilities of platinum-from ingots and stocks to the futures
market. The revived interest leads many to believe that
platinum is becoming a lucrative investment.
Accompanying this article are 22 photographs; 20 ofthese are in color and depict the variety of jewelry settings fashioned in platinum.
Jane Flannelly
A pride of boxes. N. Richardson, House d Garden, Vol.
155, NO. 5, 1983, pp. 111-117; 182-185.
The gold snuff box was an 18th-century phenomenonan object of use, luxury, and superb craftsmanship. It
was the counterpart for its time of the Renaissance pendant jewel and the 19th-century Faberg6 eggs. It cameinto being in the 1700s and remained in favor for wellover a hundred years. Because it was essentially an element of costume, its style changed as often as fashion.
In this article, the lore and lure of the gold box isreviewed with accuracy and style by Nancy Richardson,an editor at House <a) Garden, and is illustrated withsplendid photographs by Lee Boltin. The author quotes
the most authoritative sources (Kenneth Snowman,
Clare Le Corbeiller, Martin Norton, and Sir Francis Watson) and discusses examples from the most opulent andrepresentative collections (Wrightsman, Rothschild,Thyssen-Bornemisza, and ~ i r e s t o n ein) one of the bestarticles on this subject to appear in recent years.
Like most popular magazines, House o)Garden was
unable to resist the temptation to reproduce details of
many of the boxes much larger than their actual size,
thus at one stroke giving the item a misleading appearance and making the illustration less useful to the serious student. Of course, it can be argued convincinglythat House e) Garden is not aimed at serious students,
and that its greatly enlarged details give a clearer idea ofthe orecision and technical excellence of the craftsmanship. In any case, one of the most compellingcharms of the 18th-century gold box is its scale andproportion.
NL
Renk Lalique: Art Nouveau jeweler and goldsmith. K.
M. McClinton, Art ^Antiques, Vol. 6, No. 2, 1983,
pp. 90-95.
Jewelry was one of the most important expressions of

GEMS & GEMOLOGY

Winter 1983243

t h e Art Nouveau movement, and Renk Lalique(1860-1945) was the acknowledged master of the period. Prior to his time, 19th-century jewelry, dominatedby historicism, was judged by the purity and size of thestones. Lalique changed the emphasis to creative workmanship and directed attention to color, texture, andeffect rather than intrinsic value alone.
Lalioue borrowed his dominant themes from thefree-flowing forms of nature, and he mixed his materials
in dramatic and unexpected combinations-pearls withivory, opals with carnelian, plique-6-jour enamel withbone and horn. He escaped the "tyranny of the diamond"by using moonstone, peridot, amethyst, and chrysoprasei n his jewelry. T h e drooping lily, the violets of Lesbos,
the wisteria vine, and the poppy all appear in his creations. Birds fascinated him-especially swans and peacocks. Strange and eerie creatures were used as wellthe bat, the snake, and the dragonfly. Also in Lalique's
jewelry, the faces and forms of women of "fatal beauty"
emerge from disordered tresses-Medusa, Leda, Psyche,and Salome. T h e zenith of Lalique's success in jewelry
design came with the Exposition Universelle in Paris in
1900; soon afterward he began the transition from jeweler to glassmaker.
Katherine Morrison McClinton, a distinguished authority on the decorative and applied arts of the 19th
century, and author of Introduction to Lalique Glass,has written a compelling and well-balanced article on
Lalique's life and work. Her approach is not entirely
typological: she places her subject in his proper cultural
background and i s particularly informative on thechronological development of his career. The illustrations are shown in correct and comprehensible scale,and a box by Margaret Caldwell a t the end of the piece
discusses the current Lalique market and the care ofthese fragile jewels.
NL
Topkapi. A. T . Bruno, Connoisseur, Vol. 213, No. 857,
1983, pp. 67-73.
T o commemorate the 60th anniversary of the foundingof the Republic of Turkey, a special exhibition, "Anatolian Civilizations," is being held at Topkapi Palace Museum. In her article, Bruno gives a very interesting account of this major museum. She quotes once classic
description of Topkapi: "More splendid than Versailles,
more bloody than the Kremlin, and more mysterious
than the Imperial Palace of Peking." Sultan Mehmed 11,
conqueror of Constantinople, began construction of thebuilding in 1462. Enlarged by his successors, i t served as
the palace for the Ottoman rulers until 1853, when it
was replaced by a European-style palace. Topkapi wasconverted into a museum in 1923 after Kemal Ataturk
founded the Republic of Turkey.
Bruno describes in detail the various rooms andcourtyards of Topkapi, pointing out notable pieces of art
in the collection. T o many Westerners, Topkapi is best

244

Gemological Abstracts

known from a movie of the same title released in 1964
that featured the theft of a famous emerald-studded dagger. This dagger is among the 11 photographs, as is theSpoonmaker diamond, an 86-ct stone with a controversial history. These pieces are displayed in the rooms of
the Imperial Treasury, along with other gems andjewelry.
DMD

RETAILING
T h e backlash has begun. M.E. Thomas, Goldsmith, Vol.
163, No. 4, 1983, pp. 95-104.
Thomas focuses on the increased role of federal agencies
in the problem of appraisals. Using two new tax laws,
the Internal Revenue Service's involvement is becoming
ever more prominent. The direct cause of this is a combination of different events involving tax shelters andthe trading of personal and real property for coloredstones with an inflated appraised value.
Under certain government provisions, anything
overvalued will incur an additional tax liability based o n
the amount the item is overvalued. The IRS bulletin
states: "The best evidence of fair market value depends
on actual transactions and not on some artificial estimate." Fair market value defined by the IRS is the pricethe jeweler would pay.
The Federal Trade Commission's plans for dealing
with these problems do not appear to be well defined: "If
it could be demonstrated to the commissioners that theappraisal situation is scandalous or fraudulent, and they
can be convinced of this, then they might take action
against one or a number of companies," the FTC staffersays.
T h e different societies and organizations for appraisers are emphasizing the need for education in establishing values, handling conflicts of interest, and determining fees for services. However, gem traders, jewelers, and appraisers believe that laws and regulations
are not the answer. Only individual efforts will improve
the state of appraising. A handy guide to appraisal organizations follows this article.
Marcia Hucker-

Agame that hasnorules. E. Farrell, Goldsmith, Vol. 136,
No. 4, 1983, pp. 82-94.
Farrell begins this issue devoted to jewelry appraisals
with an article bearing witness to the many horror stories surrounding the world of appraising. The article
describes the efforts of a gemologist named "Joe" and his
search for t h e accurate retail value of a 1.50-ct
marquise-cut diamond. Assisting Joe in his research,staff from the Goldsmith took the diamond to a laboratory, a jewelry store, and a department store for an appraisal. The results: the appraised prices of the diamondvaried from $3500 to $6000.
T h e article stresses the need for the jeweler to establish communication with the customer and to follow

GEMS & GEMOLOGY

Winter 1983

specific guidelines when performing appraisals. Jewelers
must bc well informed about the type of merchandise
they appraise. As Jewelers Vigilance Committee's executive vice-president Joel Windman said, "If you don't
know, don't appraise."
Marcia Hucker

SYNTHETICS AND SIMULANTS
The Regency synthetic emerald. G. Brown and J. Snow,
Australian Gemmologist, Vol. 15, No. 2, 1983, pp.
57-60.
This brief article begins with an overview of hydrothermal synthetic emeralds, which were first produced i n 1960 in the form of the Lechleitner synthetic
emerald-coated beryls. This development was followed
i n the late 1960s by Linde's production of a wholly
synthetic emerald. In summarizing the Linde process,the authors note that by using natural beryl seed plates
cut at an angle to the c-axis, maximum growth could beobtained with a minimum formation of inclusions. T oproduce stones that were thick enough for faceting, themanufacturers often had to submit the crystals to anumber of growth cycles in the autoclave. In the late1970s, Linde sold its emerald-synthesizing equipment
to Vacuum Ventures, Inc. which, under license from
Linde, began'producing the Regency synthetic emerald.
Brown a,nd Snow describe the results of their macroscopic and microscopic investigations of the Regency
synthetic emerald. Observed features include a seedplate, phenalzite crystals, "dagger-like" inclusions, andoccasional flattened "healed crackN-type inclusions.
Examination of the latter two types of inclusions at 50x
revealed them to be two-phased. Eight black-and-whitephotographs augment these descriptions.
The authors provide a list of standard gemologicalproperties they determined for the Regency synthetic
emerald and conclude that, while the emeralds' synthetic origin can be determined by a combination ofdata, including refractive index (1.568- 1.573), specificgravity (2.681, and characteristic inclusions, it is notpossible to distinguish them from their Linde predecessors.
Robert C. Kamrnerling

TREATED STONES
Irradiation controversy on rubellite. D. T. Maddern,Wuhroongui News, Vol. 17, No. 1, 1983, pp. 17- 18.
Maddern's short article is in response to the controversyof whether many of the bright red rubellite tourmalines

Gemological Abstracts

that have appeared on the market i n 1983 have been
irradiated. Maddern discussed the issue with Frank L.
Davis, currently head of a mining company in Brazil,
who reported that a pocket of red tourmalines had been
discovered in the Ouro Fino mining area of Minas
Gerais, Brazil, in November 1982.
Davis argues that although a larger than usual number of small stones appeared on the market at less thanusual prices, this does not prove the stones were irradiated. Rather, i t reflects cutting and marketing decisions
made inBrazil. (It should be noted that this also does notprove they were not irradiated.) Currently, no diagnostic
test exists to detect irradiation in rubellite.
DMD
Naturally-coloured and treated yellow and orangebrown sapphires. K. Schn~etzer,G. Bosshart, and H.
A. Hanni, lournal of Gemmology, Vol. 18, No. 7,
1983, pp. 607-622.
The authors describe a new type of annealed yelloworange sapphire that has an intense color similar to thatof irradiated yellow sapphire, but is apparently stable
upon heating, at least up to 1000Â°CThe coloration ofboth natural and synthetic yellow, orange, and orangebrown sapphires is-due to their color centers and/or
various trace elements. However, differences between
natural and synthetic stones are often apparent in their
optical absorption spectra, because the trace elementsthat give rise to these colors are not the same for bothstones. Chemical data on several natural and synthetic
yellow sapphires illustrate this compositional difference.
The characteristic features of natural yellow sapphires from major localities are compared with those of
the new type of sapphire. Inclusions in this new material
exhibit characteristics found in other types of natural
corundums that have been heat treated. T h e spectra ofthese annealed yellow sapphires lack the distinct absorption bands present in natural yellow stones. The
causes of color in this annealed material are presently
unknown. T h e authors suggest that annealed and irradiated yellow sapphires can be separated from untreatednatural stones on the basis of spectroscopic and inicroscopic observations, and can be further distinguishedfrom one another by their color stability when heated/ES
above several hundred degrees centigrade.
Editor's Note: The same article appeared in German i n
the Zeitschrift der Deutschen Gemmologischen
Gesellschaft, Vol. 31, No. 4, 1982, pp. 265-279.

GEMS & GEMOLOGY

Winter 1983

245

John I. Koivula, Editor

DIAMONDS
Australia. Ashton Joint Venture (restructured into the
Argyle Diamond Mines Joint Venture and the Ashton
Exploration Joint Venture] recently sold the first consignment of its rough diamond production through theCentral Selling Organization. The Australian firm reportedly received approximately 1.9 million dollars forthe 200,000 ct, or about US$9.50 per carat.
T h e CSO starts a quarterly journal. The Central Selling
Organization has just published the first issue of its newquarterly magazine In-Sight. This new publication,
written exclusively for international sight-holders, will
be a permanent feature of the CSO's official communication program. It is designed to foster closer contact
between the CSO (seller) and its sight-holders (buyers).
In-Sight was established to clarify or correct "a great
deal of misinformation" that has caused considerable
concern among CSO sight-holders. The main purpose of
the journal will be to shed inside light on outside comment released in the general press on both the diamondindustry and De Beers.
Improvement expected in the world diamond market.
Gem and Jewellery Business Intelligence reports thatsince August of 1982, world diamond prices have remained somewhat stable. Falling interest rates in the
United States and the expectation of a continuingworldwide economic recovery among diamond-consuming nations have instilled renewed confidence i n the
diamond industry, and the future outlook is optimistic.
Japan removes import duty on diamonds. Japan has
dropped its import duty on cut gem diamonds. Thisaction could result in the expansion of Japan's diamondindustry and will certainly affect the number of diamonds purchased annually by the Japanese.
Le Grand Coeur dlAfrique. During a visit to West Africa
i n 1982, London jeweler Laurence Graff obtained a
278-ct rough diamond. After more than a year of careful
study, three stones were produced from the triangularrough. The smallest was a 14.25-ct marquise. A 25.22-ct
heart-shaped gem named Le Petit Coeur dlAfrique was
the second largest gem produced. The largest of the three
diamonds weighs 70.03 ct and is claimedby Mr. Graff to246

Gem News

be the world's largest heart-shaped diamond. Now called
Le Grand Coeur dlAfrique, this stone will eventually
carry the name of its purchaser.
COLORED STONES
India puts a ban on rough gem exports. A ban placed on
the export of rough gemstones from India is apparently
designed to stimulate the cutting industry in that country. In its annual report, however, the Gem and Jewelry
Export Promotion Council states that i t fears that such aban might adversely affect gemstone mining activity inIndia.
Opal. Information released in the trade states that opal
production in Australia fell by an estimated 60% in 1983
from 1982 levels. Fewer miners are currently seeking
opal and more mines are now inactive. These factors,
together with a lack of substantial new opal finds, have
driven prices up on all grades of opal.
Yogo sapphire. Intergem Inc. of Aurora, Colorado, presently owns the sapphire deposit in Yogo Gulch, Montana. In 1983, the mine produced approximately 200,000
ct of sapphire in limited surface mining. (The percentageof this material that was of cuttable gem quality was notreported.) Once i t has completed careful exploration, thecompany plans to put the mine into full operation.
Zoisite from Sri Lanka. Mr. Olle Fjordgren of the
Goteborg (Sweden)Gemological Laboratory reports that
i n March of 1983, while working as director and chief
gemologist of the United Gem Laboratory in Columbo,
Sri Lanka, he examined a small rough stone found in
Rakwana, south of Ratnapura. The gem was tentatively
identified as zoisite, which would be the first time thisgem has been found in Sri Lanka. The following properties were noted by Mr. Fjordgren:
Weight: 2.16 ct
Refractive index:
1.704-1.710
Optical sign: Positive,
biaxialBirefringence: 0.06
SW/LW light: Inert

Spectrum: None
Pleochroisin: Bluegreen, light blue
Specific gravity: Over 3.32
Inclusions: Actinolite (?I
needles

Readers interested i n further information on this find

GEMS & GEMOLOGY

Winter 1983

-should contact Mr. Fjordgren at Goteborgs Gemmologiska Laboratorium, Foreningsgatan 4, S-411, 27
Goteborg, Sweden.
SYNTHETICS AND SIMULANTS
More information on C-Ox. X-ray diffraction studies
donein GIA's Applied Gemology department on this supposedly "new" Russian diamond substitute (reported in
the Fall 1983 Gem News section) show that this material has a structure identical to that of cubic zirconia.
See the Lab Notes section of this issue for further information on "C-Ox."

Synthetic diamond. Using a high-energy particle accelerator, scientists at the atomic energy research establishment at Marwell, Oxfordshire, England, have succeeded in putting a layer of diamond on a preexisting
diamond crystal. The accelerator fires carbon atoms into
the existing structure of the diamond. Subsequent an-I

Accredited ~ e m o l o ~ i sAssociationts
to meet in Tucson. The Accredited
Gemologists Association is planninga gemological conference to be held
in Tucson, Arizona, concurrent withthe 30th Annual Tucson Gem andMineral Show. Topics to be coveredat the conference will include thelatest in synthetics, gemstonetreatments, and identification techniques. The conference will be heldat the Holiday Inn on South Palo
Verde Blvd. and will run from Sunday, February 5, through Saturday,
February 11. For further informationon the conference, please contact
Myriam or Tom Tashey at the AGA
editorial office, 608 South Hill St.,
Suite 1013, Los Angeles, CA 90014,
telephone (213) 623-8092.
American Gem Society to celebrate
its Golden Jubilee. The American
Gem Society has selected Atlanta,
Georgia, as the site for its first International Conclave and its Golden
Jubilee 150th year) celebration. The
four-day event, which will run fromMarch 31 to April 3, 1984, will beheld at the Hyatt Regency Hotel in

Gem News

nealing at 800Â° allows the newly added carbon atoms
to be incorporated into the diamond's lattice structure.
The added layer can be detected as a slight ridge when afinger is moved over the surface. The research team saysthat theoretically there is no reason why this techniquecould not be used to build a large gem-quality diamondusing a small crystal as a nucleus.
MISCELLANEOUS
New French postage stamp for collectors. The French
Postal Service has just issued a stamp honoring "The Art
of Jewelry." The new stamp was unveiled at the 76th
Bijorhca, the French jewelry show held annually inParis. The stamp is part of a series of stamps issued
annually by the French Post Office in collaboration with
the Soci6t6 dJEncouragementaux Metiers dlArt to honora chosen profession. Collectors wishing to obtainstamps for their collection may contact the French
Chamber of Commerce at (212) 869-1720.

Atlanta. The theme for the 1984 International Conclave is "Developing
and Promoting the Educated andEthical Jeweler." Jewelers and gemologists from all over the world
have been invited to attend. Further
information concerning the 1984
Conclave can be obtained by contacting the American Gem Society, 3460
Wilshire Blvd., Suite 914, Los Angeles, CA 90010, telephone (213)387-7375.
American Gem Trade Association to
hold gemstone congress. The American Gem Trade Association will hostan International Gemstone Congressin Acapulco, Mexico, from January
28 to February 1,1984. The agenda is
expected to include a discussion ofsynthetic gemstones and their identification, problems with treatedgemstones, appraising, inter-organizational cooperation, and the forrnation of a new international gemstoneorganization. For further information, please contact the American
Gem Trade Association at P.O. Box
32086, Phoenix, AZ 85064, telephone (602)279-7171.

Tucson 1984: the 30th Annual Gem
and Mineral Show. The entire city of
Tucson is virtually swallowed up by
this annual gem and mineral event.
The 30th Tucson show will be held
February 9- 12, 1984, in the Tucson
Convention Center, although amultitude of gem- and mineralrelated activities will be going on inarea hotels and motels before, after,and concurrent with the main "Tucson Show." The theme mineral thisyear is tourmaline, but virtually
every variety of gemstone and mineral available today can be found at
Tucson. A detailed report of thehighlights of the Tucson show willappear in the next issue of Gems o)Gemology.
Several pieces of finished jewelry,loose stones, and pocket watches
were stolen from Kenneth Cousens'(president of Kenneth Cousens, Inc.,
Santa Rosa, CAI car while it wasparked in downtown Los Angeles on
November 3, 1983. The most noteworthy piece stolen is the large sapphire and diamond necklace that wasfeatured on the cover of the Fall 1982GEMS & GEMOLOGY

Winter 1983247

issue of Gems o) Gemology. The
center stone is a 17.22-ct antique
cushion-cut sapphire. One end of theclean, medium-color stone is noticeablv wider than the other.
Among the loose stones that are
missing is an unusual 1.40-ct oval
blue sninel from Sri Lanka. There is arounded, dodecahedron crystal inclusion in one end of the cobalt-bluestone. Also included among thestolen goods were quantities of cut
rubies, sapphires, emeralds, spinels,
tourmalines, black opal, sphalerite,
and lapis lazuli.
Anyone who encounters suspicious material that might represent
any of these items is asked tocontact Mr. Cousens at P.O. Box3481, Santa Rosa, CA 95402, telephone (707)538-3614.
Many fine pearls, loose gemstones,
and pieces of jewelry were stolen
from George Brooks, of Santa
Barbara, in December. Two hundred
very fine natural gray to black,round and baroque, South Sea pearls

@^Ã

Y

5

(8%- 11Y2 mm) were taken, as well
as a large, fine collection of polished
white opal and rough (very rare) andpolished boulder opal. Included in
the loose faceted gems were a 46-ct
peridot and a superb 10-ct emerald.
Dozens of pieces of jewelry set withfine colored stones were also taken;
the hand-manufactured 18-karat
gold settings were stamped with
"Brooks."
Anyone who believes they may
have seen any of these items is
asked to contact Detective Chuck
Kennedy of the Santa Barbara Police
Department at (805)967-5561, ext.
307. A substantial reward is being
offered for information leading to
the recovery of the jewels.

American Museum of Natural
History-Central Park West and79th Street, New York, NY 10024.
Telephone (212)837-1300. This mu-

We Welcome Your Contributions.
Gems a ) Gemology welcomes newsof exhibits, events, and other itemsof a gemological nature regarding diamonds, colored stones, ornamental
materials, organic materials, gem
minerals for collectors, precious
metals, and synthetics. If you have anews item, please contact John I.
Koivula, Gemological Institute ofAmerica, 1660 Stewart St., Santa
Monica, CA 90404, telephone (213)829-2991, ext. 237.

THIRD ANNUALGEMS S, GEMOLOGY M O S T VALUABLE ARTICLE AWARD

This issue marks the end of the '1983
volume year of Gems & Gemology. Onceagain, we are asking you-our readersto select the three articles that you foundmost interesting and potentially useful. By
participating in this ballot, you not only help
us acknowledge the time and effort that theseauthors have contributed to expanding thegemological literature, but you also give us abetter idea of your needs and interests.
Your ballot is located on the insert card
inside this issue. Please choose threearticles from '1983 and mark them in order ofnumerical preference: (1) first, (2) second, (3)third. Be sure to mark only three articles forthe entire year. Additional comments
concerning the journal are welcome in thespace provided. After voting, simply detach248

seum has one of the finest displays of
gemstones and gem minerals in the
United States, if not the world. Recently on display at the museum
were three unusual gems owned byAlan Caplan of New York that haveall appeared in various issues ofGems o) Gemology: a 667-ct Muzo
emerald crystal (Gem News, Spring
19831, the 217.8-ct Mogul emerald
cover, Summer 1981),and a 15.97-ct
cushion-cut ruby from the Mogok
Stone Tract, Burma (this issue).

Gem News'ss/sisf

the postcard ballot and drop it i n the mail(postage pre-paid if mailed in the U.S.).
Ballots must be received by March 15, '1984
to be included in the final tally.
The winning articles will be announced in
the Spring ,1984 issue of Gem5 & Gemology,
with cash awards of $500, $300, and $100,
respectively, given to the authors of the threemost valuable articles.
Your participation is important to thevitality of the journal. So please take just a
few minutes now to let us know how you feel,and help honor the authors whose work has
educated and enlightened gemological readers
around the world.

GEMS & GEMOLOGY

Winter 1983

JEWELLERY OF THE
ANCIENT WORLDBy Jack Ogden, 185 pp., illus., publ.
b y Rizzoli International Publications, N e w York, 1983 (firstpublished by Trefoil Books Ltd.,
London, 1982). US$50.00*',

Jack Ogden, distinguished London
dealer and founder of The Society ofJewellery Historians, has written thefirst account of the work of jewelers
and goldsmiths of the pre-~lassicaland classical world based on the
study of materials available to themand the techniques they used in theirconsiderable achievements. H i swriting combines the sensitivity of
the connoisseur with the skill of thearchaeologist, and his book will be
useful to professionals and nonprofessionals alike.
Derek Content, one of America's
leading authorities on ancient gems
and jewelry, told this reviewer thatthe approach taken by Ogden in thisbook is long overdue. "It should havebeen written 15 years ago," Content
said, complimenting Ogden's efforts,"and 1 w i s l ~hadl written it myself."
The chapter on gemstones isnoteworthy for the review of materials used in jewelry by the ancient
craftsmen and a discussion of theirsources. The author points out theenormous potential that exists forfurther work on source correlation
for gemstones used in antiquity. The
use of emeralds, jade, lapis lazuli, organic gem materials, glass, enamel,
and faience is, of course, expected. It
is surprising, however, to find thatsuch material as cordierite, dioptase,and steatite were used. But, as Ogden
says, "There can hardly be any naturally occurring substance that has
not at one time or another been employed to decorate the human body."
He also states that the use of diamond jewelry during this period was"limited to Roman times after the
1st century and mainly to the 3rd
century."
The author gives attention to thewidespread trade in gem materials i n
antiquity, going back some 5,000
years in Egypt and India, and speculates that trade in Whitby jet andBaltic amber probably led to Medi-

Book Reviews

BOOK

REVIEWSICURRENT TOPICS IN
MATERIAL SCIENCE,
Vol. 10: "Gem Materials,
Natural and Artificial"
By I. Sunagawa, 144 pp., illus., publ.
by North Holland Publishing Co.,New York, NY, 1982. US$106.50

In both the preface and advertising
for this volume, the editor claims
that "The continuous struggles in
the gemmological laboratories toterranean sea trade with Northernfind methods for distinguishing beEurope.
tween natural and synthetic gems is
1n the chapter dealing with fakes
discussed in detail by the author
and forgeries, Ogden clearly and[Sunagawa] and presents one of thelogically pulls together all the informain scientific attractions of this exmation that has helped identify spurcellent review." However, the auious nieces for the last decade, andthor only briefly mentions a few
greatly furthers understanding of theselected aspects of this subject, andgenuine article. He says that, so far,even those are not at a level useful for
gemological tests have not been used
the gemologist.
to their full potential in forgery deThis review article contains atection, but that they have proved
their worth in several cases.
n u m b e r of interesting microtopographs of the surfaces of natural
In other parts of the book. there
and synthetic gemstones, the field of
are a few isolated facts that could bespecialization of the author. Howquestioned, e.g., "Roman agate inever, Sunagawa has attempted to extaglios are rare," when many late Repand this to cover the wide field of
public agate gems are known andthe title within a very limited space.
their popularity attested to by the
As a result, the treatment is uneven,well-known glass imitations of theindeed superficial in many places,same period. Ogden also mentions
and the reader will leave with many"rarely recorded Western Asiaticuse" of onyx, when many examples
misconceptions. For example, Sunagawa claims that a synthetic ivoryof eye "agates" in Ur and other very
has been produced (incorrect); thatearly sites are documented.
the composition of cubic zirconia is
The extensive footnotes and bibZr02-Y203 (it is approximately 9Zliography are valuable but appear inrOi*Y203]; that the color of ameextremely small print and are hard
thyst is due to iron oxides andon the eyes. The numbering system
for the illustrations is awkward, andhydroxides (it is a color center involving substitutional Fe), that thethe proofreading is not all that it
could be.
color of chalcedony is commercially
These are minor c o m ~ l a i n t s , changed by a hydrothermal treathowever, and do not detract from thement [!), and so on. There is also
luxe of the graphics, the splendor of
mention and a picture of "plastic
opal" (should be "plastic opal imitathe photographs, or the quality of thetion"). The heat treatment of amescholarship. Ogden's combination ofthyst to turn it yellow is not mentechnological and art-historical information in jewelry studies has nottioned under quartz but is discussed
as a misnomer under the heading of
been seen previously. He has broken
topaz, without ever giving the proper
new ground and established the pathname of the product. And so on.
for others to follow.
There is a brief introduction to
NEIL LETSON
crystal growth mechanisms but a t aAnniston, Alabamalevel of little use to the person who
does
not already know the meaning*This book is available for purchase atpof "Jackson's alpha." Nor do the six
the GJA Bookstore, 1660 Stewart Street,
unlabeled drawings of diamondSanta Monica, CA 90404.

Michnel Ross, Editor

GEMS & GEMOLOGY

Winter 1983249

growth apparatus in figure 20 mean
anything to the reader not already an
expert in crystal growth (and notmuch even then). The four color
plates do not do justice either to thecolor (emerald, amethyst, ruby) or to
the appearance (diamond imitations)of the materials ~ i c t u r e d There.
are
137 references with only occasional
coverage of the literature through1980. Finally, diamond is the only
gem material discussed in the textthat appears as a primary entry in theindex, and even then the wrong pagelisting is given.
Sunagawa does include highly
technical treatments of diataxy,
SbSI, nonstoichiometry, and halide
vapor complexes; workers in thesefields will find this information useful. However, the gemologist willfind little of interest in this rather
expensive volume.
KURT NASSAU
Bernardsville, Nlchapter reviews the occurrence andclassification of granitic pegmatites.
The second section includes nine
chapters dealing with various asEdited by P. Cern;, 555 pp., illus.,
pects of pegmatite mineralogy. The
publ. by the Mineralogical Associapetrology, geochemistry, and geotion of Canada, Winnipeg, Canada, logic evolution of granitic pegma1982. US$150
tites are discussed in the next five
This volume represents the pub- chapters. The final section consists
lished proceedings of a symposium of four chapters concerning the exon granitic pegmatites held i n ploitation of granitic pegmatites for
Winnipeg in May 1982, under the valuable mineral commodities. Eachauspices of the Mineralogical Asso- chapter includes a complete bibliogciation of Canada. This meeting raphy of important articles.
brought together many of the foreSince pegmatites have been, andmost authorities on pegmatites from seem destined to continue to be, theboth academic and industrial baclz- subject of only brief discussion in
grounds. As such, this volume is most geology textbooks, this volume
perhaps the most con~prehensive, appears to be the best reference on
updated text dealing with granitic granitic pegmatites for interested
pegmatites and their relationship to readers regardless of their baclimore fundamental geologic pro- ground.
cesses in the Earth's crust.
The chapters in the text fall into
JAMES E. SHIGLEY
Research Scientist, GIA
four sections. T h e introductory

OTHER BOOKSRECEIVED IN 1983

building a mineral collection;then he reviews how minerals
form, their composition a n d
structure, crystals and light, and,
finally, ways to test minerals. The
final chapter, devoted to mineraldescriptions, is arranged by chemical family. In addition to important constants and other aids toidentification, t h e author includes information on how toclean specimens and comments
on significant localities.
Depositional Systems, Richard A.
Davis, /r. Prentice-Hall. Inc.,
1983; 669 pp.; many black-andwhite photographs, line drawings, maps, a n d charts; US$33.95.
In his preface, Davis describes thisbook as a college-level textbook
on sedimentary geology. Unlike
earlier texts that were largely descriptive, focusing on sediments
and sedimentary rocks, this one
takes the genetic approach. It examines, in detail, the specific environments of deposition and

An A-Z of Gems and Jewelry, Bill
Robins. Arco Publishing, 1982; 96
pp.; 54 line drawings; US$10.95 *.
Of the 153 entries from agate tozircon, 71 are related to jewelry,
69 to gems, and 13 to metals. The
short, nontechnical descriptions
are illustrated by numerous line
drawings. These are followed by
the appendix, which is a list of 19
gemstones, their varieties, hardness, color, and main sources.
Beginner's G u i d e to Minerals,
Michael O'Donoghue. Newnes
Technical Books, 1982; 140 pp.;one color photograph, 21 blackand-white photographs, a n d 3 4line drawings; US$9.95 *. Reflecting his background in gemologicalinformation, O'Donoghue begins
with the early study of minerals
from Aristotle and Theophrastus
to Pliny the Elder. In his next
chapter h e discusses the aspects of

250

Book Reviews

SHORT COURSE IN
GRANITIC PEGMATITES INSCIENCE AND INDUSTRY

then relates these to the sedimentary features produced. An extensive reference section, 52 pages inlength, is included.
Diagrams for Faceting, Volume 11,
Glenn s)Mariha Vargas. Glenn oJMartha Vargas, 1983; 151 pp.;many line drawings; US$17,50*.
The most recent effort by Martha
and Glenn Vargas is designed toaccompany their t w o earlier
books, Faceting fur Amateurs andDiagrams for Faceting, Volume I.
Since most of these diagrams were
contributed by faceters worldwide, the authors begin with ashort biographical note on eachcontributor. Then they explain
how to convert the number settings presented i n the diagrams
into readings usable on any faceting equipment. This is followed
by 132 diagrams, arranged in 12
sections according to shape. Eachcut has step-by-step proceduresfor cutting and polishing, as well
as special notes on the degree of

GEMS & GEMOLOGY

Winter 1983

difficulty and suitable faceting
materials. This is a book to challenge experienced cutters.

!

Gem and Jewellery Year Book 1983,
ed. V. Kala. G e m s) Jewellery Information Centre of India (A-95,
Journal House, Janta Colony,
Jaipur 302004, India); 678 pp;
some black-and-white photographs, line drawings, and maps;
US$30.00*(airmail),or US$20.00(seamail). The ninth edition of
the compendium includes information about the Indian gem andjewelry trade, gemological instruments and lapidary equipment and supplies, Indiancustoms regulations, the intemational gem trade, foreign representatives in India and Indian revresentatives abroad, gem andjewelry organizations, and taxation. It also includes a directory ofIndian supplies.
Two changes in the 1983 format areworth noting. By increasing the dimensions of this year's
edition (as well as consolidatingsome chapters), the editor has reduced the number of pages from
854 in 1982 to 678 in 1983. Because each section has its own
page numbers, it was always difficult to locate specific chapters.
Now, colored sheets separate the
3 sections.

on photomicrography and one on
experimental equipment. Other
chapter modifications include
more information on synthetics
and simulants, a comparativevalue guide on equipment prices,
and a separate chapter on thermal
conductivity. Once again, manufacturers and suppliers are listed
in the appendix.
Lapidary Carving, Frank W. Long.
Van Nostrand Reinhold, 1982;
132pp; 102 black-and-whitephotographs, 52 l i n e drawings;
USs24.95 *. Long begins by defining different types of carving aswell as briefly reviewing the history of carving from a 40,000year-old figure to today's commercial work. In his second chapter he discusses materials, grouping them by hardness. In the thirdchapter, he focuses on carving
tools and equipment. This is particularly interesting because heincludes equipment not traditionally used by lapidaries. Linedrawings and photographs amply
illustrate his fourth section on
methods and techniques. He
concludes this useful book with ashort chapter on design fundamentals and an appendix withpertinent references such as speed
tables and supplies of equipment
and materials.

Gemmological Instruments, Peter
G. Read. Butterworths, 2nd ed.,
1983, 328 pp; m a n y blaclz-andwhite photographs, as well as
m a n y line drawings; US$39.95 *.
Read has increased the text in thissecond edition by 101 pages andincluded two new sections, one

Minerals and Rocks of Jamaica, Anthony R. D. Porter, Trevor A.
Jackson, and Edward Robinson.
Jamaica Publishing House, 1982;
174 pp.; 12 color photographs, 10
black-and-white photographs,
three maps, and five line drawings; US$12.95. The authors,

Book Reviews

three Jamaican geologists, combined the basics of a rock andmineral handbook with the specifics of localities in Jamaica.
They divided the book into twoparts: minerals and rocks. In part
1, chapters on minerals and thephysical properties of minerals
are followed by a description of
Jamaican minerals and Jamaicanmineral identification. In part 2,
chapters on rocks and on a description of Jamaican rocks arefollowed by rock identificationand the geologic history of Jamaica. Locality information is
keyed to topographic and geologic
maps which are described in the
appendix. There is also a reference
list with 93 entries.
Rocks, Minerals and Gemstones ofSouthern Africa, E. K. Macintosh.
C. Struik (Pty) Ltd., 1983; 120, pp.; 109 color photographs;
US$15.00 *. This collecting guideto mineral resources in southern
Africa begins with short chapterson collecting and on the physicalproperties of minerals. The majority of the book is composed ofbrief descriptions of materials divided into chapters: major andminor rock-forming minerals; igneous, sedimentary, and metamorphic rocks; and minerals of
economic importance. This lastchapter has been added since thefirst edition appeared in 1976.
Locality information is a usefulaspect of the descriptions. The
color photographs are quite good,giving a visual example of most of
the rocks, gems, and minerals
presented.

GEMS & GEMOLOGY

Winter 1983

251

GEMS & GEMOLOGY is an international publication of original contributions (not previously publishedin English) concerning the study of
gemstones and research in gemology
and related fields. Topics covered
include [but are not limited to] colored stones, diamonds, gem instruments, gem localities, gem substitutes (synthetics),gemstones for thecollector, jewelry arts, and retailmanagement. Manuscripts may besubmitted as:
Original Contributions-full-length
articles describing previously unpublished studies and laboratory or
field research. Such articles should
be no longer than 6,000 words (24double-spaced, typewritten pages]
plus tables and illustrations.
Gemology in Review-comprehensive reviews of topics in the field. A
maximum of 8,000 words (32 double-spaced, typewritten pages) is
recommended.
Notes & New Techniaues-briefpreliminary communications of recent discoveries or developments ingemology and related fields (e.g., new
instruments and instrumentation
techniques, gem minerals for thecollector, and lapidary techniques or
new uses for old techniques]. Articles for this section should be about
1,000-3,000 words (4-12 doublespaced, typewritten pages).
MANUSCRIPT PREPARATION
All material, including tables, legends, and references, should be typed
double spaced on 8'/2 x 11" (21 x 28
c m ) sheets. The various componentsof the manuscript should be prepared and arranged as follows:
Title page. Page 1 should provide:(a)the article title; (b)t h e full nameof each author with his or her affiliation (the institution, city, and stateor country where helshe works); and(c)acknowledgments.
Abstract. The abstract (approximately 150 words for a feature article, 75 words for a note) should state
the purpose of the article, what wasdone, and the main conclusions.
Text. Papers should follow a clear
outline with appropriate heads. For
example, for a research paper, theheadings might be: Introduction,

252

Suggestions for Authors~ w e s t b nr fors
Authors
Previous Studies, Methods, Results,
Discussion, Conclusion. Other heads
and subheads should be used as the
subject warrants. For general style,see A Manual of Style (The University of Chicago Press, Chicago).
References. References should be
used for any information that istaken directly from another publication, to document ideas and facts
attributed to-or facts discovered
by-another writer, and to refer thereader to other sources for additional information on a particularsubject. Please cite references in the
text by the last name of the author(s1and the year of publication-plus
the specific page referred to, if appropriate-in parentheses (e.g., Liddicoat and Copeland, 1967, p. 10).
The references listed at the end of
the paper should be typed double
spaced in alphabetical order by thelast name of the senior author. Pleaselist only those references actuallycited in the text (or in the tables orfigures].
Include the following- information,in the order given here, for each reference: (a)all author names (surnames followed by initials); (b)theyear of publication, in parentheses;c ) for a journal, the full title of thearticle or, for a book, the full title ofthe book cited; and (d)for a journal,
the full title of the journal plus volume number and inclusive page
numbers of the article cited or, fora book, the publisher of the bookand the city of publication. Sample
references are as follows:
Daragh P.J., Sanders J.V. (1976)
Opals. Scientific American, Vol.
234, pp. 84-95.
Liddicoat R.T. Jr., Copeland L.L.
( 1967) The lewelers' Manual, 2nded. Gemological Institute ofAmerica, Santa Monica, CA.
Tables. Tables can be very useful inpresenting a large amount of detailin a relatively small space, andshould be considered whenever thebulk of information to be conveyed
in a section threatens to overwhelm
the text.
Figures. Please have line figures(graphs, charts, etc.) professionallydrawn and photographed. High-contrast, glossy, black-and-white prints
are preferred.
Submit black-and-white photographs and photomicrographs in the
final desired size if possible.
Color photographs-35 m m slides
or 4 x 5 transparencies-areencouraged.
All figure legends should be typed
double spaced on a separate page.
Where a magnification is appropriate and is not inserted on the photo,please include it in the legend.
MANUSCRIPT SUBMISSION
Please send three copies of eachmanuscript (and three sets of figuresand labels) as well as material for all
sections to the Editorial Office:G e m s &> Gemology, 1660 Stewart
Street, Santa Monica, CA 90404.
In view of U.S. copyright law, acopyright release will be required on
all articles published in Gems elGemology,
No payment is made for articles
published in Gems &> Gemology.
However, for each article the authors will receive 50 free copies of
the issue in which their paper
appeared.
REVIEW PROCESS
Manuscripts are examined by the
Editor, one of the Associate Editors,
and at least two reviewers. The authors will remain anonymous to thereviewers. Decisions of the Editor
are final. All material accepted for
publication is subject to copyediting; authors will receive galley proofs
for review and are held fully responsible for the content of their articles.
GEMS & GEMOLOGY

Winter 1983

IndexVolume 19
Numbers 1-4,1983
SUBJECT INDEX
T h i s index gives t h e first a u t h o r ( i n parentheses) and first page of t h e article, Editorial Forumlor
G e m T r a d e Lab N o t e s ( G T L N ) section in w h i c h t h e indexed subject occurs. T h e reader isreferred t o t h e a u t h o r index for t h e full title a n d t h e coauthors, w h e r e appropriate, of t h e articles
cited.

I

A
African padparadscha, see Sapphire
Alexandrite
cat's-eye (GTLN)43, 171
Alexandrite effect, see Color changeAmber,in plastic (GTLN) 171
Andraditephysical and optical properties of(Stockton) 202
Aquamarine
from Kashmir (Atkinson) 64
Arcot diamonds(Krashes) 21
Art Deco jewelry
origins, characteristics, materials
used, and designers of (Ebert) 3
Assembled stones
garnet-and-glass doublet(GTLN)43
ruby-synthetic ruby doublet(GTLN)43
Aztec Sun God opal
(Koivula) 87

B
Book reviews
Antique a n d Twentieth Century
Jewellery (Becker] 127
Classic Mineral Localities of theWorld: Asia a n d Australia(Scalisi and Cook) 57
Current Topics in Material
Science, Voll0"Gem Materials,
Natural a n d Artificial"(Sunagawa) 249
Diamond Cutting(Watermeyer)57
Diamonds and Diamond Grading(Lenzen) 189

Index

Gems: Their Sources, Description,and Identification, 4th ed.
(Webster, Anderson) 189
The Gemstone Identifier(Greenbaum) 189
Glass Engraving (Norman) 57
Jewellery of the Ancient World(Ogden) 249
Jewelry Concepts e.0 Technology(Untracht) 127
lewelry on Display (Coutchie) 57
The Lizzadro Collection(Lytle) 127
Minerals of Broken Hill (Wornerand Mitchell, eds.) 189
Practical Gemcutting (Perry) 127
Short Course in Granitic
Pegmatites in Science andIndustry (Cerny, ed.) 149
V N R Color Dictionary of
Minerals and Gemstones(OIDonoghue) 127
Brazilimperial topaz from (Keller) 12
Brazilian ruby, see Topaz
Briolette of India diamond(Krashes) 21
Bruce Winston Heart Shape diamond(Krashes) 21
Burma
Mogok Stone Tract-history,geology, mining, andfamous rubies of (Keller)209c
Cameo(Gray) 191, (Keller)97
Capao do Lana Mine, see Brazil
Cartier, Louis(Ebert)3

Cat's-eye, see Chatoyancy
Change-of-color phenomenon, see
Color change
Chatham, Carroll,(Liddicoat] 129
Chatoyancy
in alcxandrite (GTLN)43
in opal (GTLN)43
in quartz (GTLN) 43
in scapolite (Schmetzer] 108
in zircon (GTLN) 232
Chevet(Gray) 191
Chhatrapati Manick
40-ct ruby fromBurma (Keller)209
Chloromelani tewith maw-sit-sit (GTLN) 232
Chrome pyrope, see Garnet
Coatings
on beryl to imitate emerald(GTLN)43
Cobalt glassas lapis lazuli imitation(Bosshart) 228
Colombiaoiling of emeralds from
(Ringsrud) 149
Color change
in alexandrite (GTLN)43
in spinel (GTLN) 43
Colored stones
computer program to identify(Read) 157
from Mogok Stone Tract,
Burma (Keller)209
use of GEM DiamondMasterto separate (Hoover) 77
use of, in Art Deco jewelry(Ebert) 3
Computer

GEMS & GEMOLOGY

Winter 1983

253

program to identify gemstones(Read) 157
C-Ox, see Cubic zirconia
Cubic zirconia
with laser drill holes (GTLN) 171
marketed in Europe as C-OX(GTLN)232
submitted as diamond (GTLN)112
see also Diamond simulants

D
Deal Sweetener diamond(Krashes)21
Demantoid, see Andradite
Deutsches Edelsteinmuseum of
Idar-Oberstein, Germany(Keller) 97
Diamondwith abraded facet junctions[GTLN] 171
carved (GTLN)43
coated (GTLN) 112, 171
and Harry Winston (Krashes] 21
inclusions in, dendrites[GTLN) 232
use of, in Art Deco jewelry (Ebert)3
Diamond, coloredpink (GTLN)43, 112
yellow (GTLN) 112, 232
Diamond, cuts and cutting ofrose cut (GTLN) 112
Diamond simulants
detection of (Hoover) 77
see also Cubic zirconia
Diaspore( GTLN) 17 1
E
Editorial
Carroll Chatham 1914- 1983
(Liddicoat) 129
synthetics manufacturers(Liddicoat] 63
Edwardes ruby167-ct ruby crystal (Keller)209
Egyptian blue, see Lapis lazuli
substitute
Emerald
oiling process and detection of(Ringsrud) 149
spiral growth pattern in(GTLN) 171
treated (GTLN] 43
Emerald, synthetic
flux-grown with unusual
inclusions (GTLN) 43
hydrothermal from USSR(GTLN] 112
Enamelinguse of, in Art Deco jewelry (Ebert)3

254

Index

Engraved gems
history, engraving process,materials used, andrecent developments of(Gray) 191
Enstatite(Stockton) 103
Estate jewelry[Krashes] 21

FFire opal, see Opal
Fluorite(GTLN) 43
Fossils
in gemology [GTLN]43, [Editorial
Forum) 169

G
Garnetpyrope, rhodolite, almandine,classification of(Hanneman) 37, (Manson] 41
see also Andradite
Gem carving
collection of (Keller)97
and engraved stones (Gray) 191
Gem collections, see Museums andgem collections
GEM DiamondMasterand thermal properties of gems
(Hoover) 77
Geneva ruby, see Ruby synthetic
Gibbsiteas turquoise imitation [GTLN)112
Glyptic arts (Gray) 191
Greened amethyst, see Quartz

H
Heat treatmentof amethyst (GTLN) 232
new Japanese furnace [GTLN)232
of pink diamond (GTLN)43
of ruby and sapphire (GTLN) 232
of topaz, pinking (Keller) 12
of yellow sapphire (GTLN) 232
Hope diamond(Krashes) 21

IInclusions
in amethyst (Editorial Forum] 169
in andradite [Stockton) 202
in cat's-eye scapolite(Schmetzer) 108
i n cat's-eye zircon (GTLN) 232
in cobalt glass (Bosshart)228
in diamond, dendrites (GTLN]232
in heat-treated yellow sapphire(GTLN)232

induced fingerprints inflame-fusion rubyand sapphire (Koivula] 220
in lapis lazuli (Bosshart) 228
in opal from Querktaro, Mexico(Koivula) 87
in Ramaura flux-grown synthetic
ruby [Kane) 130
in ruby from Burma (Keller] 209
in sapphires from Kashmir(Atkinson)64
in synthetic emerald(GTLN] 43, 112
in Verneuil synthetic ruby(GTLN)232
India
Kashmir sapphire mines of(Atkinson)64
Intaglio(Gray) 191
Irradiationof topaz (Keller) 12
of yellow sapphire (GTLN) 112

J
Jade substituteglass (GTLN) 171
serpentine (GTLN) 232
Jadeitedyed blue (GTLN) 112
Jewelry design
Art Deco (Ebert)3Jonker diamond(Krashes) 21

K
Kunz, George F.
new manuscript of (Editorial
Forum) 11 1

L
Lapis lazuli substitutecobalt glass [Bosshart] 228
Egyptian blue (Bosshart) 228
new imitation (GTLN) 171
Laser drillingof cubic zirconia (GTLN) 171

M
Maw-sit-sit
with chloromelanite (GTLN] 232
Melanite, see Andradi te
Mexicoopal deposits of Querktaro(Koivula) 87
Minas Gerais, see Brazil
Museums and gem collections
Burma ruby in (Keller] 209
Deutsches Edelsteinmuseum of

GEMS & GEMOLOGY

Winter 1983

Idar-Oberstein, Germany[Keller)97
engraved gems in (Gray) 191
padparadscha in [Crowningshield) 30

N
Niarchos diamond(Krashes) 21
Nomenclature
discussion of, as applied toclassification of red-to-violet
garnets [Hanneman]37,(Manson] 41
of padparadscha [Crowningshield] 30
Nur-ul-ain tiara(Krashes)21

0
Oilingof emeralds (Ringsrucl) 149
Opal
cat's-eye (GTLN) 43
dyed oolitic (GTLN] 43
from Querktaro, Mexicolocation, history, mining,gemological properties, andinclusions of (Koivula] 87
unusual specimen (GTLN) 112
Opal, synthetic
black, Gilson (GTLN] 171
white, Inamori (GTLN) 232
Oriental hyacinth, see Sapphire,!

Padparadscha, see Sapphire
Peace ruby43-ct stone from Burma(Keller)209
Pearlsbadly eroded (GTLN)232
black non-nacreous "pearl"[GTLN] 112
use of, in Art Deco jewelry (Ebert)3
Pearls, cultured
button (GTLN] 43, 171
freshwater (GTLN) 43, [Editorial
Forum] 111
Mabe (GTLN] 112% cultured blister pearl[GTLN) 232
Peridot
from Tanzania-chemistry andproperties of(Stoclzton) 103
Petrol and Mineral Development
Corporation (PMDC]
gem auctions in Burma(Keller] 209

Index

Finite[GTLN) 171
Pinking, see Heat treatment
Platinumuse of, in Art Deco jewelry [Ebert]3

Q
Quartzblue (Bosshart) 228
chatoyancy in [GTLN)43
green (GTLN) 112
reddish brown (GTLN)232
rose (GTLN) 43

Ramaura ruby, see Ruby, synthetic
Ringsignet (Gray) 191
Rubyfrom Burma [Keller]209
damage by heat treatment(GTLN)232
heat treatment of, in Sri ~ a n k a(GTLN) 232
Ruby, synthetic
early Verneuil, "Geneva Ruby"[GTLN) 232
flame-fusion, use of in Art Deco
jewelry (Ebert) 3
flux, Ramaura-history, crystal
structure, gemologicalproperties, and separations of[Kane) 130
induced fingerprints in(Koivula) 220
Ruby-synthetic ruby doublet, see
Assembled stoness
Sapphirefrom Kashmir, India-history,geology, gemologicalproperties, notable stones,
and current situation of(Atlzinson) 64
padparadscha [Crowningshield)30
yellow (GTLN) 112, 232
Sapphire, synthetic
flame-fusion, use of in Art Deco
jewelry (Ebert) 3
synthetic padparadscha(Crowningshield]30
Scapoli tecat's-eye, from Sri Lankaphysical propertiesof and cause of chatoyancy
in [Schmetzer) 108
Scarab (Gray) 191
Seals
cylinder, scarab, scaraboid,

ringstone (Gray) 191
Serpentine
as jade substitute (GTLN) 232
Spectraof andradite [Stoclzton) 202
of cobalt glass (Bosshart] 228
in cubic zirconia [GTLN) 232
of enstatite (Stoclzton] 103of peridot (Stoclzton) 103
of Ramaura synthetic ruby
(Kane] 130
Spectrophotometry
use in separation of natural fromsynthetic rubies[Kane) 130
Spectroscopy
infrared, to identify turquoise[Lind] 164
Spinelcolor change in [GTLN)43
Sri Lanka
cat's-eye scapolite from
[Schmetzer) 108
heat treating of ruby and sapphire(GTLN) 232
sapphire from (Crowningshield]30- Star of the East diamond[Krashes) 21
Star of Independence diamond(Krashes) 21
Star of Sierra Leone diamond[Krashes) 21

T
Taaffeite[GTLN) 112
Tanzania
peridot from [Stoclzton) 103
sapphire from (Crowningshield)30
Tanzanitewith rounded facet junctions(GTLN] 171
Thermal conductivity[Hoover] 77
Thermal inertia(Hoover) 77
Thermal propertiesof gem materials, synthetics, andsimulants (Hoover] 77
Topazimperial, from Brazil-history,geology, mining, andgemological properties of[Keller) 12
Topazolite, see Andradite
Tourmalinefrom Kashmir [Atlzinson] 64
Treatment
healing fractures in natural andsynthetic gemstones(Koivula] 220

GEMS & GEMOLOGY

Winter 1983255

Trilobite(GTLN] 43
Turquoise
identification of, by infrared
spectroscopy and X-ray
powder diffraction(Lind) 164
separating natural from treatednatural, synthetic, andsimulants (Lind) 164
Turquoise, substitute(GTLN) 112
Turquoise, synthetic
separation from natural (Lind) 164u
Unclassified oddities
organic concretion (GTLN) 43

v
Vargas diamond[Krashes) 21w
Winston diamond(Krashes) 21
Winston,. Harry(Krashes) 21
Wristwatches
Art Deco style [Ebert)3x
X-ray powder diffractionuse of, to identify turquoise(Lind) 164z
Zirconcat's-eye (GTLN)232
Zoisite, see Tanzanite

AUTHOR INDEX
T h i s i n d e x lists, i n alphabetical order, t h e n a m e s of a u t h o r s of a l l articles t h a t appeared in thefour issues of V o l u m e 19 of Gems <t> Gemolow. Full c i t a t i o n i s provided u n d e r t h e first a u t h o r
only, with reference m a d e from joint a u t h o r s .
AAtkinson D., Kothavala R.Z.:
Kashmir sapphire, 64-76

Hoover D.B.: The GEM DiamondMaster and the thermal propertiesof gems, 77-86

K

B
BankH., see LindT. andSchmetzerK.
Bosshart G.: Cobalt glass as a lapis
lazuli imitation, 228-23 1cCrowningshield R.: Padparadscha:
What's in a name?, 30-36

E
Ebert J.M.: Art Deco: the period, thejewelry, 3- 11F
Fryer C., see Koivula J.I.

G
Gray F.L.: Engraved gems: ahistorical perspective, 191-201

H
Hanneman W.W.: A newclassification for red-to-violet
garnets, 37-40

Kane R.E.: The Ramaura synthetic
ruby, 130-148
Keller P.C.
The Capao topaz deposit, Ouro
Preto, Minas Gerais, Brazil,
12-20
T h e newly expanded Deutsches
Edelsteinmuseum of IdarOberstein, Germany, 97- 102
T h e rubies of Burma: a review ofthe Mogok Stone Tract,209-219
Keller P.C., see Koivula J.I.
Koivula J.I.
Induced fingerprints, 220-227
Koivula J.I., Fryer C., Keller P.C.:
Opal from Queretaro, Mexico:
occurrence and inclusions,87-96
Kothavala R.Z., see Atkinson D.
Krashes L.S.: Harry Winston: a story
told in diamonds, 21-29

L
Liddicoat R.T. Jr.
Carroll Chatham, 1914- 1983,129

Synthetics manufacturers: somehelp, some hinder, 63
Lind T., Schmetzer K., Bank H.: The
identification of turquoise by
infrared spectroscopy and X-ray
powder diffraction, 164- 168

M
Manson D.V., Stockton C.M.: A
response to "A new classification
for red-to-violet garnets,'' 41 -42
Manson D.V., see Stockton C.M.

R
Read P.G.: A computer program for
gem identification, 157- 163
Ringsrud R.: The oil treatment ofemeralds in Bogota, Colombia,
149-156s
Schmetzer K., Bank H.: Investigationof a cat's-eye scapolite from Sri
Lanka, 108- 1-10
Schmetzer K., see Lind T .
Stockton C.M., Manson D.V.
Gem andradite garnets, 202-208
Peridot from Tanzania, 103- 107
Stockton C.M., see Manson D.V.

Indexes prepared b y Dona Dirlam

256

Index

GEMS & GEMOLOGY

Winter 1983