The Van Buren press., 1894-12-01
MYSTERIES c.. THE RUBY.
Gr,raord,nary reta,hf!dies Presented ia
LIS trIii.. ~.

Its straeture.
In an address before tie Royal Insti-
tat.on in London, Prof Judd said that
jewels and their history is of insignif-
cant interest compared with the fas-
cinating aetualities which science has
discovered in regard to the wonderful
gem family-the aristoerats of the min
eral kingdom. Eight years ago England
was excited over the annexation Of
Burmah, and there were great expecta-
tions of what was to happen when the
British capitalist got his hands on the
celebrated ruby mines of that kingdom.
Somehow or other these expectations
have not been gratified.
The rubies are not forthcoming, but
1t is not to be presumed from this that
Burmah has enjoyed a false reputation
for those remarkable stones of price.
Prof. Judd showed that while the ruby
and its near relations are found in
many parts of the globe. it is in Bur-
nah alone that the gem is unearthed
in its purest and most fiery form. The
intense pigeons blood color and Pc
culiar fire" of the Burmese ruby give
it extraordinary value as compared
with other red stones which come into
rivalry with it, for under the name of
''rubies'' a great variety of gems not
truly entitled to the name have in an
cient and modern times passed muster.
The only substance which can truly
be called ruby is pure, 1impid, fiery
red corundum. This mineral, eorun-
DUN, is crystallized oxide of aluminium,
and forms the basis of nearly every
gem (excert, Of course, the diamond)
which we value for hardness, brill
liancy and color. A crystal of pure
red corundum we call ruby crys-
tai of the blue variety is priced as a
sapphire green crystal we know
as an emerald" and other tints are
known as aquamarine topaz, and so on.
Corundum is found very widely distrib-
uted in the east, especially in Gey,on,
Thibet and Afghanistan, and in the
United States big masses of impure
blood-red corundum are found, from
which isolated crystals can be cut, and
thus entitle the Americans to claim
the ruby as native product. There
are great many red rivals to the Bur-
mese ruby, but with the exception of
the red diamond none is SO hard. They
include the red spinel, the rose topaz,
red zircon, rubellite "a form of tour
maline more priced in China than the
ruby, and the various garnets. This
quality of hardness is one of the most
valuable features in the ruby, for it
enables the gem to take high polish.
The diamond is of course harder, and
it is interesting to note that one of the
first products evolved from the cleo
trical furnace crystallized compound
of carbon and silicon-is only less hard
than the diamond itself.
The chief scientific interest Of the
ruby corundum flows from the extraor-
dinary peculiarities of structure that it
presents as well as from the mysterious
qualities that determine its striking
color. 1t is found in crystals of great
variety of shapes, but all having ten
dency to the peculiar habit of growth
known to crystallographers as twin
ming" BY testing crystals of corun-
dunn with polarized light its structure
is found to be wonderfully complex,
and under the microscope it's exterior
face is covered with strange network
of sculpture, indicative of molecular
changes.
But probably the most interesting
thing about the corundum crystal is
the fact that it is nearly always found
to have enclosed and surrounded some
foreign body or other. which lies i'm
prisoned in it.. Stranger still is the
fact that these included foreign bodies
lie generally disposed of in planes
meeting each other at an angle of sixty
degrees, the result being to produce
the phenomenon of asterism, which is
the term given to the white star of
light which is observable on certain
Jewels cut with rounded surface.
Very frequently the imprisoned body
is minute bubble of gas or drop of
liquid containing sometimes little
crystals of its own.
The microscopic cavities containing
these things are often very numerous.
For long time the nature of the gas
and fluid in the cavities remained a
mystery. The English philosopher,
Brewster, was induced to Investigate
the subject by hearing that ruby
which an Edinburgh jeweler had
placed in his mouth had exploded
while in that position, with unpleasant
results. Other Investigators followed,
and it has now been made certain that
the fluid is no other than liquid car
bonic acid gas, reduced to that con-
dition by being under great pressure.
The color of the ruby is another of
it's mysteries, and one upon which Prof
Judd was only able to touch upon
slightly in his lecture. The color is
distributed most irregularly, and some
corundum crystals show in patches the
tints of the ruby the sapphire, and the
emerald all mixed together. These
colors are, of course, due to the special
way in which the structure of the crys-
tai deals with the light passing through
it, the ruby absorbing all the rays ex-
cept those which emerge TO give it its
characteristic color.
How greatly these colors depend on
molecular and chemical changes going
on in the crystal is obvious from the
strange way some gems behave under
light and heat. Prof. Maskelyne mem
tions diamond which. when taken out
of the warm pocket and allowed to cool
on the table, turned beautiful red
Prof. Judd startled his audience by de-
claring that the green glass panes used
in the conservatories at Kew gradually
changed through various shades of yell