San Antonio daily light. [volume] (San Antonio, Tex.) 1886-1907, 1892-12-01
CONTEMPLATING GEMS.
A Peculiar Glass the Basis of Imi-
Iation-ReaI Gems Will Prob
ably Be Produced Ar

"A
tation-ReaI Gems Will Prob
ably Be Produced Ar
Iificiallj.
From the Washington Star.
"The finest initiation diamonds are
made out of rock crystal" said
Washington dealer in precious stones.
1.-THE basis of the most successful
coun terfeits of all kinds of gems is
pure, very dense and highly trans
parent sort of glass, which is termed
paste in the trade. For false dia
nouds this glass is simply cut and
I o ished in facets, while for initiating
other stones, sach as rlbies, emer-
aids, sapphires, etc metallic oxides
are mixed with 1t.
I'm manufs curing glass for such
purposes she processes employed have
to Dc conducted with the utmost
uicety. For making even the best
mirrors the necessary silica Is OBJ
tanned from ordinary white quartz,
while common window panes are
produced from Sc, sand to a large ex'
tent; but, in this case, rock crystal Is
substituted, composing about 80 per
cent of the ingredients of the paste.
To it must be added % per cent of
car Donate OF soda and due proportions
of calcined boraX. saltpeler and red
lead. All of these things are reduced
to the finest powder, mixed, fsued to
gether by heat in crucible and cooled
slowly.
The density, trans parency and
beauty of the plate depend upon the
care taken in these processes. Thus
made, 1t is all ready to be cut up into
diamonds and prepared Tor market.
1t may be, however, that the manu-
facturer desires to produce ounterfeit
gems OF other sorts. IL so, he has the
means readily at hand. Surprising
that he wants rubles, he fuses with
paste q small quantity OF peroxide of
maganese and q trace OF Cassius pur-
pie, which will give the proper color.
For emeralds, he employs in like
manner oxide of iron, and for sap
phires oxide of cobalt.
"Topaz is easily formed in the cru
chile by mixing with 1000 parts OF
paste 40 parts of glass of anthony
and part of Cassius purple. For
manufacturing other Kinds of gems
there are other methods equally
simple. OF course, none of these I'M
itation precious stones has the chemi-
cal constitution, hardness, specific
gravity, or optical properties OF real
ones. Accordingly, their falseness Is
readily perceived by an expert mas
much as the elements of which va
rious gems are composed are wei!
known, synthetic chemistry has at
empted to reproduce them by put
ting the ingredients together and eff
feet ng capitalization in the labora-
tory. In this way large masses Of
what might be termed true ruby and
sapphire are turned out artifically,
such gem like material having some
usefulness for industrial purposes,
although lacking the brilliancy of
natures products.
"For my wn part, / am confident
that sooner Oh later some, If not ali, OF
the stones deemed precious will be
reproduced by artifice. The chemists
who have hitherto confined their at
ten ton to taking things apart are be-
ginning 10 learn how to put them to-
gether All the gems are very simp
in composition and the problem is
merely to make their elements crys-
talize properly. In all such knowl.
edge scien, has made but little pro-
gress as yet. We do not even know
tor what reason one substance is
transparent while another is Opaque,
though presumably there is some re-
lation between the arrangement of
the molecules in the transparent body
and the length of the light waves,
which, in the case Of the transparent
body, permits the latter to pass
through"