The
following summary includes only a few of the principal features in the
precious stones industry in the United States since 1882:
Diamond.—Only
scattered finds were reported in various States, some in river and
glacial gravels, and others loose in the soil, until 1906 when diamond
was found associated with decomposed peridotite matrix in Arkansas.
Since that time 2,000 to 3,000 stones have been found on the surface
and by washing the earthy matrix. The value of the Arkansas deposits
has yet to be demonstrated.
Sapphire.—A
few sapphires were saved from the placer gold mining along Missouri
River near Helena, Mont., until about 1890 when active mining for the
sapphire was undertaken in connection with mining for gold. In 1891 and
for several years following mining was continued successfully. In 1893
placer sapphire deposits were discovered along Rock Creek in Granite
County. In 1894 more placer sapphire deposits were found along Dry
Cottonwood Creek, in Deer-lodge County, and near Yogo Gulch, in Fergus
County. The Yogo sapphires are nearly all true sapphire blue and were
soon traced to their original matrix, from which they have been mined
almost continuously to the present. All of the other placer sapphire
deposits produce only varicolored stones, including no pure blue gems.
They are used principally for mechanical purposes, such as meter and
watch bearings.
Ruby.—Occasional
rubies were found in the corundum deposits of North Carolina and
Georgia. The best find of ruby was made in 1893 in Cowee Valley of
Macon County, N. C, in placer deposits. A few fine gems were found and
later the stones were traced to their original matrix, where
prospecting has been tried at various times without definite results.
Topaz.—Topaz
mining has never reached an important stage in the United States Since
1882 the more important finds have been on Baldface Mountain, near
North Chatham, N. H., in 1888; in San Diego County, Cal., about 1903;
and in Mason County, Tex., in 1904. These deposits, as well as others
in Maine, Colorado, and Utah, are only intermittently worked. The
majority of the topaz from the United States is colorless, but some
fine blue and bluish-green crystals are found.
Emerald.—The
principal emerald localities of the United States are in North
Carolina, but a few inferior emeralds have been found in Maine and
Connecticut. In North Carolina the emerald-hiddenite mine has already
been referred to. After 1891 operations were limited to a little
intermittent prospecting, the last of which was in 1907. In 1894
emerald was found on Crab tree Mountain in Mitchell County, N. C, and
mining was conducted for a few years. This locality did not produce
clear gem emeralds, but a quantity of stones were cut with the white,
gray, and black associated matrix and sold under the name of emerald
matrix. In the same year, 1894, a stray emerald of good color was found
near the North Carolina-South Carolina State line, south of Shelby.
This was a forerunner of the discovery of the emerald deposit on the
Turner plantation, 5 miles southwest of Shelby, in Cleveland County, N.
C, in 1909. This deposit was worked by the Emerald Co. of America and
yielded the best colored emeralds so far found in the United States.
Work was stopped in 1913.
