to
several causes, among which are the deposition of the different
minerals or colors in agate-like bands either around a fragment of
other mineral as a core or filling cavities however formed, and the
brecciation of both the variscite and matrix with subsequent
deposition of other minerals or of the same mineral with different
shades of color in the cracks and seams. Among the odd combinations of
color may be mentioned light-green with deep-green "cobweb" or
"turtle-back" mottling, with or without other colored matrix; dark
brown or yellow matrix in seams and irregular masses with light or dark
green background, or vice versa; yellow, gray, and white matrix
inclosing or inclosed in green of varying shades.
Mr.
Don Maguire reports a considerable production of utahlite, or
chlor-utahlite, from the Camp Floyd mining district, Utah County, about
2 miles south of Mercur gold mine. This locality has been described by
Dr. George F. Kunz in his reports on the production of precious stones
for 1894 and 1904.
GEM MINERALS OP SOUTHERN CALIFORNIA.
Mining
for precious stones in San Diego County was actively pushed during the
first part of 1907, and a considerable output was obtained. During the
last half of the year operations were but intermittent or suspended at
a number of the mines. The principal production of gems came from
around Mesa Grande and Pala, though there was a smaller production from
Rincon, Ramona, Riverside, Oak Grove, etc. At Pala varying amounts of
work were done at the Pala Chief and Tourmaline Queen mines, owned by
the Pala Chief Gem Mining Company; at the Stewart Lithia mine, or its
extension, owned by the American Lithia Company; at the Caterina,
Hiriart, and Naylor-Vanderburg mines on Hiriart Mountain, owned by the
Sickler Gem Mining Company; and on claims on the north side of Hiriart
Mountain. At Rincon there was an output of tourmaline and kunzite from
the Mack mine. At Mesa Grande work was done at the mines of the
Himalaya Mining Company, the Mesa Grande Consolidated Gold and Gem
Mining Company, the San Diego Gem Mining Company, the Native Gem Mining
Company, the J. M. Cota mine, the Trail mine, and the Rose Quartz mine.
At the mines on the hill 4 miles N. about 70° E. of Ramona the Little
Three, Hercules, Lookout, Reliance, and Mars claims and the Daggett
mine were tested or worked.
PALA.
Stewart Lithia mine.—The
Stewart Lithia mine is located about a mile and a half northeast of
Pala on the end and along the east side of a ridge or spur of a
mountain. The vein consists of a pegmatite mass neaily 50 feet thick in
places and outcropping prominently for a third of a mile or more; part
of the outcrop to the north belongs to the Messrs. Labaugh. It has a
northerly strike with a gentle dip (10° to 15°) to the west. The
principal work has been to the south for lithia minerals at the point
of the spur where the pegmatite ledge outcrop extends from the east
side to the west side. Tunnels have been cut through the ridge exposing
large masses of lepidolite and amblygonite. Compact lepidolite can be
obtained here by the hundred tons. Later work at the Stewart mine
consists of several cuts 51506—M b 1907, FT 2------53
