Iron County register. [volume] (Ironton, Iron County, Mo.) 1867-1965, 1888-02-02
PRODUCED BY FUSION.
y Dishonest Dealers Have Tr;ctsa e..
Purchasers of Rubies


Purchasers of Rubies
Among the papers included in the
report on mineral resources of the
United States just issued from the &C.
ological Survey Office is one bv GEORGE
/. Kunz. the well-known expert in
gems, on precious stones. A portion
OF TINS article is devoted to artificial
rubies- 1t seems that early in the
summer the syndicate DIES diaments ct
pterres prectemses was informed that
certain stones which had been sold as
rubles from new locality were sus-
pected to be of artificial origin. They
were put upon the market by Geneva
firm, and it was surmised that thew
were obtained by the fusion of = LARGE
number of small rubies, worth at the
most few dollars carat. into one
fine gem worth from 81, 900 to s.. 500
per carat.
Some of these artificial stones were
examined by Mr.. Kunz. but he was
not permitted to break them for
analysis. to observe the cleavage, or
to have them cut so as to observe
the optical axes more correctly. Tt
was possible, however, to detect their
artificial nature with mere pocket
lens. as the whole structure was that
peculiar to fused masses. Among the
principal differences between these
and the genuine stones was the pres
ence in them of large numbers of
spherical bubbles, rarely pear
shaped, sometimes containing strinpv
portions showing how the bubbles
bnd
vidually they always seemed to be
filled with gas or air, and formed
part Of cloud. the rest having the
wayiness of fused mixture. In nat
ural rubies the cavities are ALWAYS
angular or crystalline in outline, and
usually filled with some liquid. or if
they form part of a feather as it is
called by the jewelers.. they are often
arranged with the lines of growth.
Hence the difference in appearance be-
tween the cavities in the natural gem
and those in the fused gem is very
great, and can readily be detected by
the pocket lens.
Another distinguishing characteris-
tic is that in many genuine rubies
there is a silky structure (called silk"
by the jewellers,) which. if examined
under the microscope. is found to be
series of cuneiform or acicular crys-
tails, often iridescent and arranged
parallel with the hexagonal layers of
the crystal. When in sufficient num-
Der these acicular and arrow-shaped
crystals produce the astoria or star
effect. if the gem is cut en- cabocho,,
no of+ he
prism on the top of the cabochon.
Mr.. kunz failed to find them
in the artificial stone, or even any
of the markings of the hexagonal
crystal, which often can be seen when a
gem is held in a good light and the
light allowed to strike obliquely across
the hexagonal prism. The hardness
of these stones was found to be about
the same rs that of true ruby, 8 8.
or trifie less than 9. the only differ
ence being that the artificial stones
were trifle more brittle.
The specific gravity of these stones
was found to be s. SO and s. 95. The
true ruby ranging from 3.93 to 1.01. it
will be seen that the difference is very
slight and due. doubtless. to the pres
ence of the included bubble in the ar
tificial stones, which would slightly
decrease the density. The color of
all the stones examined was good,
but not one was so brilliant as a very
fine ruby The cabochons were all
duller than Fl ne. true stones, though
better than poor ones. They did not
differ much in color, however, and
were evidently made by one exact proc
ess or one at time. Their dull APP
pearance is evidently due to the bub-
bles.
The French syndicate referred the
matter to NJ. Friedel. of the School of
Mines. Paris, supplying him with SAM
Piles of the stones for examination. He
reported the presence of the round and
pear-shaped bubbles. and determined
the hardness and specific gravity to
be about the same as of the true ruby.
On analysis he found them to cons list
of alumina, with trace of chromium
for the coloring matter. He states
that he himself has obtained small red
globules with these inclusions by
fusing alumina by oxyhydrogen light;
and, although having no positive evil
dence. he believes these stones to be
artifcially obtained by fusion. On
receipt of NJ Frieders report the syn
dictate decided that all cabochon or cut
stones of this kind shall be sold rs
artificial and not as precious gems.
All sales effected thus far, amounting
to some 6O0 600 or 800. 600 francs.
shall be Cancelled and the money and
stones returned to their respective
owners The syndicate has thus fully
settled the position which this produc-
ton will take among gem dealers.
Mr. Kunz says. and there is little rea-
son to fear that the ruby will ever lose
the place it has occupied for SO many
centuries. Philadelphia Press.