The evening telegraph. [volume] (Philadelphia [Pa.]) 1864-1918, 1867-03-19

the upper sides and corners are called bezel-
the name collet is given to a.small plane at
the bottom. The top is styled the crown; the
facets are triangular spaces and faces; the table
is plane ON top; then there are guides, ribs,
lozenges, pavilions, etc.
The brilliant is composed Of face or table
surrounded by facets, which is all that is
visible above the bezel when set The stone
in depth below the bezel should equal half its
breadth. On the under side it terminates in
a small table, connected with the upper sur
face by elongated facets.
The rose is fiat below, and cut with facets
over the upper surface-a sort of half poly
hebron resting on the plane. 1t is a pretty
figure.
The table is an appropriate form for thin
stones with large surfaces. It is cut at the
edges into facets.
The lasques are fat stones.
TESTS
In the trade it often happens that colorless
topa2es, emeralds, sapphires, and white zir-
oous are palmed off for diamonds. 1t is often
matter Of great difficulty to detect a real
diamond from another stone, or from an imi-
tation. There are various tests for the dia-
mond. Thus the diamond will merely refract
rays Of light which will pass through other
gems. Electric tests can be instituted between
diamonds and other stones. The specific
gravity of the diamond is another test. Then
its color. The peculiar brilliancy of the dia-
mond when cut is another excellent test; but
we would advise all who desire to purchase
diamonds to visit the experts connected
with the leading jewelry-houses, who
make diamonds a study, and who
claim that having once seen a dia-
mOnd, they never forget it, and can always re-
cognize it, no matter what changes may have
taken place in the cutting or setting. Flaws
often exist in genuine diamonds, and these
| flaws are not seldom difficult to discover. To
detect flaw, breathe on the surface of the
stone. This swill dimish thelustre of the gem,
| and the flaw will be rendered apparent. Dia-
monds 'off color" as they are termed, are
very faulty, though very common, sometimes
one-half the stone is genuine, the other half
| being an imitation. These "doubets" or
''semi-stones" are common and very deceitful.
Sometimes colored matter is placed in the set
| ting, to give the desired hue to the gem.
STANDARD OF VALUE.
There is an arbitrary rule, which has been
extensively followed, to determine the value
| of a diamond. The gem is measured by carats
| (equaling four grains), these grains differing,
| however, from Troy grains, five of the one
| equalling four of the other-and the rule is
multiply the square of the weight in carat by
certain sums, varying according to the stone,
its manner of cutting, ETC. The rule now
| seems to be, if a diamond of l carat is worth
| 500, a two-carat diamond will be worth 2X2
times that sum, or $400; three-carat 3x3
that sum, or $780, and so on. This rule applies,
however, only semi-occasionally. With all
the really valuable gems, the universal custom
is for the seller to ask as much as he thinks
the buyer will by any possibility pay. After
! all, diamonds, like other commodities, regu-
late themselves. Large gems are more valua-
| ble in proportion than small ones; but, on the
other hand, small gems are by far the most
likely to find purchasers. The carat is divided
into siXty-tour parts, so as to express all lhe
variations of weight, which, in so precious a
substance as the diamond are matters of great
moment.
In the United States, before the war, the
following table was published of the value of
! diamOnds:-
Per Carat.
One-carat to 500
Melle or mixed stone..".........".....,0O % to 90
Two-caraL TO 4O0
Three-carat to 600
But these prices have been greatly increased
of late years; and the general rule of value
seems to be to ask whatever one is likely to
get.
All sorts of prices have been paid for dia-
mOnds. Some time since, stone of 81 carats
sold for f33, coo, while larger stone has sold
for less. Different prices have been asked and
|
but, as a rule, though the exact market price
of a diamond may vary, yet it always has a
certain ratio of genuine value.
! Diamonds too, are affected in value by their
history and associations. In a catalogue of a
| recent collection, we observed the following
l. Drop-shaped brilliants, 40 grains, for
merly belonging to Louis XVI.
2. Brilliant drops, 1909 grains, formerly be-
longing to Marie Antoinette.
3. Rose diamonds, 63 grains, formerly be-
longing to Sultan Selim.
4. Brilliant drops, 1909 grains, formerly be-
longing to Joseph BOnaparte.
Who will deny that the value of gems thus
historically associated with terrible memories
is vastly in excess of their mere worth as sin
| gle stones
| MISCELLANEOUS USES.
Diamonds have commercial and utilitarian
! value outside of their character as Jewels.
The rougher varieties of diamonds are used
| for miscellaneous purposes, and are called by
| the technical term ''tort." Diamond-powder
is extensively employed by lapidaries and
| gem-engravers: also, for etching points. The
point OF diamond is used by GLACIERS for the
cutting of glass. Only the point of a natural
crystal can be used for this purpose.
INVITATIONS.
The enormous value of the diamond has, of
course, stimulated attempts to initiate it, and
these attempts are oftentimes very successful:
The French have been especially successful
in this line Mons. Bourquignon has become
| celebrated as a manufacturer Of imitation dla-
monds. He obtained his sand from Fontalne-
beau Set in gold these limitations look ap-
solutelv as magnificent as the genuine gem;
| They, however, lose hardness and grow 9Gh 5!l
| IN t;,,,a Tl,a ,,otarial used for initiating dla-