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GEMS AND PRECIOUS STONES IN THE
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color
of the different varieties recommended its use in the arts, and it
exists in such immense quantities that it should receive some attention
from jewelers and decorators.
Pitchstone
is a variety having the lustre of pitch rather than glass. Pitchstones
are often albite or oligoclase rather than or-
OBSIDIAN
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thoclase ; that is, they contain soda, or soda and lime, instead of potash as a base.
The
best known crystals of chondrodite, and the finest known gems cut from
this material, have been found at the Tilly Foster Mine, Brewster, Ν.
Υ. Recent working has brought to light transparent, garnet-colored
crystals, measuring 1/2 by 1/2 inch, and a few over 4 inches across.
One essonite-colored crystal is 1/4 inch
CHONDRODITE
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across.
Others, still uncut, would furnish fine gems. The finest of these
crystals are in the Allen Cabinet, now at the Johns Hopkins
University, in Baltimore, Md., and in the Mineralogical Cabinet of the
Peabody Museum, New Haven, Conn. The cabinets of Frederick A. Canfield
and Clarence S. Bernent also contain
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