The Irish standard. [volume] (Minneapolis, Minn. ;) 1886-1920, 1892-12-31
INIT TII(lN GEMS.
uow Many Kinds OF Precious
Stones Are Counterfeited.
ADook Crystal Plays an Important Part In
the Manufacture Of Artificial jew
els-One Result of Progress
SO In Chemistry.

The finest imitation diamonds are
's1ade out Of rock crystal" said Wash
s1gton dealer in precious stones to
star man recently 1.-THE basis of the
.nost successful counterfeits of all kinds
Of gems is a pure. very dense and highly
tranEparent sort of glass, which is
sermed paste in the trade. For false
diamonds this glass is simply cut and
yolished in facets, while for initiating
ether stones. such as rubies, emeralds,
Iapphires, etc, metallic oxides are
mixed with it.
'41n manufacturing glass for such pur-
9sses the processes employed have to
be conducted with the utmost nicely.
Tor making even the best mirrors, the
Necessary silica is obtained from ordi-
nary white quartz, while common win
Sow panes are produced from sea sand
- = large extent; but, in this case, rock
arystaI is substituted, composing about
WITTY per cent of the ingredients of the
caste To this must be added twenty
Two per cent. Of carbonate of soda and
sue proportions Of calcined borax, salt
gster and red lead. All of these things
IRE reduced to the finest powder, mixed,
fased together by heat in crucible and
s.ooled slowly.
1.-THE density. transparency and
beauty of the plate depend upon the
sare taken in these processes. Thus
saade, it is all ready to be cut up into
diamonds and prepared for market It
tray be, however, that the manufac-
2urer desires to produce counterfeit
xems of other sorts. If SO, he has the
saeans readily at hand. Surprising that
ne wants rubies, he fuses with paste
ANAL quantity of peroxide of manganese
xnd trace of Cassius purple, which
will give the proper color. For emer-
y1ds, he employs in like manner oxide
pf iron and for sapphires oxide of CO.
talt
''Topaz is easily formed in the cr,dci~
Ade by mixing with one thousand parts
q paste forty parts OF glass OF anti
nony and one part of Cassius purple.
For manufacturing other kinds of gems
there are methods equally simple. OF
course, none of these imitation precious
stones has the chemical constitution,
Hardness, specific gravity or optical prop
xrties of real ones Accordingly their
salseuess is readily perceived by an ex-
pert. Inasmuch as the elements OF
which various gems are composed are
veil known, synthetic chemistry has
attempted to reproduce them by putting
the ingredients together and effecting
specialization in the laboratory. In
this way large masses of what might De
termed true ruby and sapphire are
>urned out artlicially, such ge,n-ike
material having some usefulness for in
dustrial purposes. although lacking the
Srilliancy of natures products
''For my own part, | am confident
that sooner or later some, if not all, OF
the stones deemed precious will be re-
produced by artifce. The chemists who
have hitherto confined their attention
TO taking things apart are beginning to
learn how to put them together. All
Che gems are very simple in compost
tion and the problem is merely to make
Nheir elements crystalline properly. In
Ill such knowledge science has made
kut little progress as yet. We do not
sven know for what reason one SUBJ
stance is transparent while another is
opaque; though presumably there is
some relation between the arrangement
Of the molecules in the transparent
body aud the length of the light waves,
which, in the case Of the transparent
body, permits the latter to pass
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