Evening star. [volume] (Washington, D.C.) 1854-1972, 1903-03-14
TEST OF DIAMONDS.
There Are Very Many Ways of Detect
ing limitations.
From the London Express.

From the London Express.
Anyone can tell a genuine diamond or
precious stone even from a very clever imi-
tation. There are few household tests
which are practically infallible. The dia-
mond expert, after long experience with
gems. can detect an imitation, as a rule,
at a glance. The layman in such matters,
with few simple tests, takes more time
to solve such problems, but his judgment in
the end is scarcely less accurate.
An imitation diamond is never so brilliant
as genuine stone. If your eye is not ex-
perienced enough to detect the difference,
very simple test is to place the stone I'M
der water. The imitation stone is practi-
cally extinguished, while a genuine dia-
mond sparkles even under water and is dis
tinctly visible. When possible place a gen.
uine stone beside the possible imitation I'M
der water and the contrast will be appar-
ent to the least experienced eyes.
The glass-cutting test is, of course, more
or less familiar. 1t is probably the most
common. False diamonds are usually cut
more regularly than the genuine stones In
cutting diamond the material is saved so
far as possible. In any imitation the ma
terial is itself worthless, and no effort is
made to suit the size or angle of the facets
to the form of the stone. 1t can be put
down as safe, rule that when a stone is
cut with great evennesS and regularity it
is, to say the least, very suspicious sign.
Another very simple and effective test is
to place a drop of water on the stone and
carefully observe the result. The stone
should be first carefully cleaned. On an
imitation diamond the drop, however small,
will deliquesce. The drop will, however, re-
tain its original shape on true stone. To
make the test quite sure use magnifying
glass when watching the action of the
drop. ~
Still another test of this nature is to pass
the stone over a piece OF aluminium. Both
the metal and the stone should be abso-
lutely free from any trace of grease. The
metal will give off some Of its color to an
imitation stone, while a genuine diamond
will remain perfectly clear and unaffected.
Among jewelers. the final test Is to apply
drop of fiuohydric acid to the stone under
suspicion. The acid will eat into any false
diamond and frost it, while the genuine
stones will not be damaged in the slight
est degree.
Perhaps the simplest method Of all, how
ever, is to examine an ink spot on a sheet of
white paper through diamond by holding
the upper surface against the eye. If the
stone be counterfeit the black spot will
appear greatly multiplied, or at least dou-
bled. The outline will. moreover appear
blurred and indistnct. By using a magni-
solute.
The optical test is the best In examining
rubies and emeralds. It is commonly sup
posed that such stones can be best tested
by rubbing them with file; that the gen.
uine stone resists the steel. while the imi-
tations only will suffer: but the test is not
exhaustive. The best plan is to examine
them closely with a microscope of about 100
diameters. The genuine stones have num-
Der of minute flaws. whereas the limitations
are likely to be much more nearly perfect
in texture.