322 mineral resources, 1914—part ii.
through
pale bluish-green to bright bluish-green exteriors. Some of them are
associated with smoky quartz in rude crystals and rough tabular albite
crystals. Plates of biotite occur with these minerals. Much of the
amazon stone is striped with gray to white perthitic markings, but a
few specimens do not show more of these markings than is ordinarily
present in amazon stone used for gems. The best specimen submitted to
the Survey showed a bright translucent bluish-green color. This
specimen could not be cut into a pure gem, but would contain some
perthitic markings. A few of the amazon stones have been cut as gems,
but none have been regularly placed on the market.
SUNSTONE. ARIZONA.
Specimens
of andesino feldspar, some of which showed the characters of sunstone,
were received from Dr. H. P. Wightman, of Globe, Ariz. Dr. Wightman
states that these were collected by the Apache Indians from then
reservation not far from Globe. The specimens resemble the sunstone
from Modoc County, Cal., cut by the Pacific Gem Co., of Los Angeles,
mentioned in this report for 1913. Microscopic examination shows it to
be andesine with a refractive index of 1.550. All of the andesine is
clear, one piece showing a pale-yellowish color and the other bright
copper-colored reflections from inclusions along certain lines of
crystallization parallel to one of the cleavages.
GARNET.
ALASKA.
A
deposit of garnet about 7-1/2 miles north of Wrangell, Alaska, from
which many fine specimens have been obtained during the last 15 years,
is being developed by the Alaska Garnet Mining & Manufacturing
Co., of Minneapolis, Minn. The bulk of the garnet taken from this
deposit is used for a special foundry powder, but many of the fine
crystals, with their associated mica schist matrix, are sold for
cabinet specimens, and gems are reported to be cut from occasional fine
specimens. A good exhibit of the garnets is being made at the
Panama-Pacific International Exposition. The crystals range from small
size up to more than an inch in diameter. They show face developments
of the rhombic dodecahedron and trapezohedron faces. The small faces
are fairly sharp, and where they meet at the dodecahedron points show
a dark-red color tinged with violet, characteristic of almandine
garnet.
JADE.
ALASKA.
Some
of the jade from the Shungnak region north of Kobuk, Alaska, was cut by
lapidaries of San Francisco during 1914 in preparation for the
expected increase of trade in souvenir gems among visitors to the
Exposition. This jade is the dull dark-green variety of nephrite.
