Weekly graphic. [volume] (Kirksville, Adair Co., Missouri) 1880-1949, 1884-03-21
Cutting and Setting Precious Stones.

Crystalline gems, like diamond and
topaz, are generally cut in such man
ner so TO have flat, smooth faces. Prec-
ious stones that decompose the light and
thus produce Il play of colors; are polish
ed in such Il manner rs TO hcighten this
effect as much rs possible, which is ac-
complished by making large number
of small facets This brilliant is an ex-
ample.
Precious stones that do not crystal
lie, and are distinguished by play of
colors. like the opal, or peculiar effects
of light, like the cats eye, are usually
polished round or oval like loaf OF
bread or :. haf Of IN egg.
Gems are set in two different WAYS,
distinguished as free setting (ajouv)
and band setting zen cassette). In the
former the stone is exposed on all sides
and only held by little clasps. All its
properties. its fire. its play of colors.
show to the best advantage here.
Hence very valuable gems are never set
in any other way. Flat stones that are
set in rings are sometimes fastened on
the edge so rs to leave only the top and
bottom surfaces exposed.
In band setting the stone forms the
lid of 4 gold box, and if the gem is
transparent the upper surface is gener-
ally made Hat and smooth, while the
under side forms low pyramid.
In those stones which receive n band
or box setting, and are less valuable,
the beauty of the stone is increased by
lining the box with colored tin foil the
| color of the foil corresponding to that
of the stone. Thus. for example, II
piece OF dark yellow foil is placed under
very pale topaz. a deep purple foil I'M
der pale amethyst, an so on. so that
the light reelected from beneath through
the stone will have u deep yellow or
violet color, giving the stone much
finer appearance than if it were set
free.
When setting common stones in cheap
goods. they do not take the trouble to
line the box with tin foil. but merely
give it coat of some colored varnish.
This method is not one 10 be recon-
mended, for 4 stone that has the foil
beneath it looks much handsomer.
| In order to make a cheap article with
genuine stones the following ingenious
device is resorted TO: Thin slips of
some gem, as emerald, for example. are
backed up with glass OF exactly the
same color, and the glass likewise
polished. BY setting one of these doub-
lie stones with the real stone outward
and the glass beneath, the surface will,
of course, exhibit, all the properties OF
of the gem. such as hardness, etc
These half genuine stones are known rs
''underlaid gems, or in French rs
''DierreS fines doubice." When these
underlaid gems are skillfully set, it is
difficult even for the expert TO distin-
guish them from perfectly genuine
stcHes. But still it is easy to distinguish
them by holding the stone before the
eye in such manner that the light re-
Elected from the top enters the eye at an
oblique angle; the surface where the
stone and glass meet can be distinctly
recognized by the difference in the re-
! fractive power of the two media. hav-
ing the appearance of q crack or flaw
in the stone. The public are frequently
deceived by dealers who represent these
underlaid stones as being perfectly gen
uine.-- NeucSte ErfnduHgen.