St. Landry clarion. (Opelousas, La.) 1890-1921, 1901-07-27
TESTING PRECluos STONES.
Several Methods Of Identifying Genuine
Jewels.

Several Methods Of identifying Genuine
Jewels.
Genuine diamonds are generally
recognized At first glance BY the jew
Ieler, with the naked eye, and surely
with the aid Of the magnify fying glass,
says the Jewellers Circular w eekly.
a greater refraetion is pereeptibleI
when the genuine diamond is placed
under water together with the i1nita-
ton. The latter is extinguished to in.
visibility, while the genuine stone
sparkled even under water and is dis
tinetly visible. # the diamond be
passed over a piece Of window glass,
it will penetrate without use of force
and ae glass may be broken BIZ rery
slight pressure. a false stone scratches
| the glass but specifically.
Il drop Of water be placed By
means Of d needle on the stone to be
tested, which has previously been.
thoroughly cleaned, the drop viii
spread ont on an imitation, while IL
retains its drop shape on q true dia-
mond. A strip Of aluminium may be.
passed over a diamond from which
all grease has been removed without
i acquiring even a trace oft; on imi-
tations, however, the metal viii give
off some of its color.
A sure medium is also fiuorhy hydric
acid, which is kept IN caoutchouc bot
ties, since It eats into glass and all
silicious compounds, including false
diamonds, and frosts them, while the
genuine diamond issues unscatched
from the test, retaining its full bril-
iancy. If one makes an inkspot on
white paper and views it through the
stone, a counterfeit can be recognized
By the fact that the spot appears null
tiplied (double) and with indistinct
outlines.
A spurious diamond is usually cut
much more regularly than genuine
one, for in the latter q certain limit
is observed, SO as to spare the valua-
BILE material as far as possible, while
in the worthless material of the imi-.
tation there is nothing to Be saved.
Therefore, striking regularity ofthe
cut Is a suspicious sign.
Very well known is The test for
hardness; if the stone resists strong
attacks, it IS certain to be genuine;
il it can be ruined with steel file, the
damage is insignificant, as only an
imitation has been destroyed. The
test, however, does not hold good ii
the case Of other stones. It is true,
q ruby which can be affected by q
steel file or BY quartz is suspicious,
but the emerald IS scarcely harder
than quartz and such d test with
topaz Is liable to injnre q valuable
stone.
For examining rubies and emer-
aids the optical test is best. A glass
about 100 diameters suf-
fees. Every expert knows that al
most ali precious stones have little
flaws. Nearly every ruby and all en-
eralds have many defects, which are
SO characteristic that the gennineness
Of the stone is readily established. |
Such a test is very necessary with
rubies, because limitations are quite
deeeiying; their color being absolute
ly durable and often much finer than
that Of the genuine, although It may
be stated that d somewhat yelloWish |
lint is always suspicious.
The only reliable way in which |
genuine rnbles can be told from irni- |
tations is by the minute air bubbles |
Of the latter, which become clearly |
visible under the nagnifying glass.
These are not to be found in the nat
ural gem; On the other hand, theimi-
tations lack certain defects character |
lstic Of genuine rubies certain vac |
uums, whose outlines are much more
than those of the air Dub |
bles of the limitations.
Emeralds are always afflicted with
characteristic defects, which, how
ever, prove their genuineness, such
il Enclosures Of liquids, as well as IN
;losures of peculiar dendritic, j. e., /
reelike, shape. Sapphires likewise
show peculiar netlike formations.