furnished
by them is considered confidential and that only the combined figures
of production are published. The Geological Survey conducts a large
correspondence on the subject of precious stones, and accurate
information furnished by the individual producers enables the Survey to
put intending purchasers of rough material directly in touch with them.
Under
miscellaneous gems in the table of production are included apatite,
calamine, chlorastrolite, crocidolite, cyanite, datolite, fossil coral,
Iceland spar, lazurite, obsidian, peridot, phenacite, rutile,
smithsonite, spodumene (kunzite), staurolite, thomsonite, titanite, and
zircon.
RANK OF STATES.
Montana
leads all the other States in the value of precious stones produced in
1915, a position it has held for the last five years. The output
consists chiefly of sapphires, which constituted almost one-half of the
total value of all precious stones produced in the United States in
1915. Moss agate was also a considerable item, the value ranking next
to that of sapphires. Montana also produced some garnet and Iceland
spar in 1915.
California
ranks second in value of precious stones produced, the larger items
being tourmaline, jasper, chalcedony, and agate, vesu-vianite
(californite), and spodumene (kunzite). Small quantities of beryl,
garnet, rock crystal, smoky quartz, rose quartz, chryso-prase, topaz,
diamond, and lazurite were also produced. A large
S
production of kinradite, the spherulitic jasper from the vicinity of an Francisco, is noted.
Nevada produced chiefly turquoise and opal, with smaller outputs of copper ore gems and variscite.
Colorado
produced various precious stones, jasper and chalcedony having the
greatest value. Pyrite, smoky quartz, and feldspar gems were also
produced, as were garnet, rock crystal, amethyst, rose quartz,
turquoise, topaz, hematite, phenacite, and rhodonite.
Arizona
produced chiefly turquoise and also garnet and the copper ore gems.
Small outputs of smoky quartz, chrysoprase, onyx, aga-tized wood,
crocidolite, peridot, obsidian, and jasper were reported.
Utah produced chiefly variscite; New Mexico, turquoise; Alaska,
g
arnet; Virginia,
staurolite; Maine, the pegmatite minerals, tourma-line, topaz, beryl,
and smoky quartz; and Arkansas, diamond, rutile, garnet, rock crystal,
and smoky quartz.
Value of precious stones produced in 1915.
Montana.................................................... $105, 355
California................................................... 22, 312
Nevada.................................................... 6, 333
Colorado.................................................... 5,987
Arizona................................................... 4, 998
Oregon..................................................... 4,252
Utah, New Mexico, Alaska, Virginia, Maine, Arkansas '....... 16,952
Other States2............................................... 4,242
170, 431
i Production of each State more than $1,000 and less than 14,000.
' Massachusetts,
Michigan, North Carolina, New Hampshire, Idaho, South Dakota,
Connecticut, Minnesota, Kansas, Pennsylvania, New York, South
Carolina, Texas, Wyoming. Production of each State lees than 11,000.
