The record-union., 1894-07-12
PRECIOUS STONES.
They Are Doctored to Increase Their
Seeming Value.
Clever Deceits successfully Carried
Out-Colors skilltully Used to
Conceal Imperfections.

The value of diamonds and other gems
depending mainly upon their bulk, the
efforts of the falsifiers have been chiefly
directed to increasing the proportions.
The principal mode of so doing is known
as ''doubling." 1t was in use in the sew
enteenth century, and a case before the
law courts in reference TO so-called rule
shows that it is fiourishing. 1t consists
in joining together with cement portion
of real stone and an imitation, so as to
make the combination appear one and
indivisible. This can be done SO deity
that the initiated are sometimes de-
ceived. So long as combination of this
kind remains unset the expert discovers
it usually by a close examination of the
edges; when it is mounted, in ring,
bracelet or other setting, recognition is
practically impossible. This is the most
common form of deceit in the jewel trade.
If some of the jewels priced by noble and
princely houses were taken to pieces nd
carefully examined by an expert, the re-
suit might astonish the owners. Some
surprising discoveries of this kind have
been made when family jewels were be-
ing remounted.
It is to guard against deceptions of this
kind that jewellers and dealers in stones
decline to buy gems In their settings.
When the gem is unset 1t can easily be
subjected to ready and infallible test. A
stone about which there may be sus-
picion is dropped into dish of very hot
water. If it is ''doublet' the cement
quickly disSolves and the component
parts fall assunder. But 'doublets" are
also made in which the real diamonds
finds no place. The art of glass manu-
facture has made many advances In re-
cent years, and experience has taught
those who make 1t their business to fab
rieate spurious gems that better result
and closer imitation of the genuine arti-
Gle can be obtained by joining two pieces
of glass OF diverse shades. 1t is man
aged in this way: The top portion of the
false brilliant is made from glasses in
which there is pale yeNow or straw
colored tinge. In the under side of
this a socket is drilled into this
socket is fitted a stem of glass of light
blush shade, the result OF the combina-
ton being that the false stone CLEANS and
sparkles like a gem OF the purest water.
The best limitations Of this description are
SO effective that when mounted they de-
ceive all but the best judges.
Among the tests used by dealers and
jewellers to ascertain not only the reality
but the quality of diamonds offered for
Few professionals are without a case of
proved diamonds, graded according to
their degree of hardness. All purchases
are tested by this scale, and their quality
ascertained. A specially constructed
microscope is used to distinguish colors
in stones. 1t has been stated that dia-
monds are seldom bought by the trade
after they are mounted. They are gen
orally taken out of the setting for inspec-
ton. This is. more especially the case if
the stones are so mounted that the under
portion is hidden. One of the Oldest
tricks of the trade is to so color the bed in
which the stone rests as to change the
hue of the gem. For instance, a ruby
will glow with deeper and more in
tense fire if the bottom and sides of the
setting wherein it is fixed be colored red.
The shade of stone can be altered or
flaw concealed by the skillful use of col
ors in this way. Naturally this device
does not deceive the initiated. A perfect
stone is invariably mounted "a jour-" or
so that every part of it is visible.
The discovery OF diamonds in South
Africa led indirectly to some clever de-
ceit by the dealers. Many Of the South
| African diamonds have straw tint,
which has an unfavorable effect on their
price, especially as experts believe that it
will become more decided the longer the
stones are exposed to the air. Some of
| kD6 more kuOWluS u6d1STS ulScOV0TSN
! that by subjecting the straw stinted dia-
monds to a bath of certain acids the OBJ
| jectionable color was removed and the
gems became pure white. A number of
diamonds so treated were sold in Paris
and Berlin, and brought high prices than
they would if they had retained their
original color. After exposure to the
action of the air for a certain time the
original color returns, but by that time
/ tbpv have paSspd ont the dealers' hands,
| The fraud was soon found out by the
trade. and they now guard against impo-
sition of such character by means of
various tests. Of these the most gener-
ally used are the hot water bath and fric-
tion. II dyed stone be left in hot water
for few minutes it resumes it's original
hue; or if the gem be rubbed sharply on
a towel or even on the coat sleeve, its
normal color can be detected. These
tests are simple and eftieaeious and are IN
daily use.-Pall Mall Gazette.