the
discovery of a new tourmaline deposit in pegmatite inclosed in
garnetiferous mica schist in Fremont County, Colo. A new deposit of
tourmaline was reported from the Pala region, San Diego County, Cal.,
by Mr. John W. Reed, late in 1907. A pocket opened in this deposit
contained over 150 crystals, some 2 or 3 inches in diameter and
several inches long, which had a lavender color. Several tourmaline
mines in California are described under the "Gem minerals of southern
California."
INDIA.
The
production of tourmaline from the Ruby Mines District of Burma during
1906 amounted to 193 pounds, valued at £1,001,-as compared with 161
pounds, valued at £1,500 in 1905.° Mr. E. C. S. George, deputy
commissioner of the Ruby Mines District, describes the workings for
tourmaline " about a mile east of Maingnin. These deposits were
worked by the Chinese about 150 to 200 years ago. According to local
tradition they were again opened temporarily by Kachins about forty
years ago. About 1885 the deposits were reopened and more
systematically worked until 1895 under Pir Seinde. Since 1899 they have
been worked by licenses, and during the last three years this locality
has produced about £200 worth of tourmaline annually.
The
tourmaline occurs in soft, decomposed, granitic veins, generally
covered by a thick layer of jungle soil. Isolated crystals are
sometimes found in the yellowish earth associated with the granite or
the red soil capping it. The discovery of the deposits made from shafts
4 or 5 feet square with underground workings is almost entirely
accidental. Some of the shafts are about 100 feet deep, which seems to
be the limit of the native skill. The tourmaline is sorted into three
classes: (1) Best pink rubellite; (2) darker colored crystals, lower
part brown or black; (3) fragmentary crystals of any color, or
imperfect small crystals. The best varieties bring from £80 to £100
per viss (3.65 pounds).
TURQUOISE.
There
was a production of nearly 600 pounds of rough selected turquoise and
of nearly 3,000 pounds of turquoise matrix during 1907, from Arizona,
Nevada, Colorado, New Mexico, and California. The greater part of the
production came from the mines near Mineral Park, Ariz. The output from
Colorado came from the mines near La Jara, Conejos County, operated by
the Colorado Turquoise Mining Company. This company reported
development work by two tunnels 200 feet and 100 feet long,
respectively, and four shafts 105 feet, 97 feet, 70 feet, and 50 feet
deep, respectively. Mr. E. H. Davis, of Mesa Grande, Cal., mentions the
discovery in December, 1907, of a turquoise deposit in the Colorado
desert on Carrizo Creek. Turquoise seams in a dark matrix are
especially suitable for cameo coverings, and some of the native
material has been used with excellent results for this purpose by
Messrs. F. J. Essig, of Chicago, and William Petry, of Los Angeles.
This turquoise cameo stone comes from Esmeralda County, Nev., and
consists of good blue turquoise in seams an eighth of an inch or more
in thickness in a dark gray chalcedony matrix. The latter furnishes a
good background for the turquoise carving.
o Rec. Geol. Survey India, vol. 36, pt. 2, 1907, p. 83
