AGATE.
CALIFORNIA.
A
deposit of fine blue chalcedony or agate was prospected during 1913, by
F. M. Myrick, about 37 miles east of Johannesburg and about 2 miles
northeast of Lead Pipe Spring, in the Death Valley region, California.
The deposit was discovered by Joe L. Foisie and located in January,
1911, as the Sard claim. The title was allowed to lapse and new
locations were made by Mr. Myrick, with the approval of Mr. Foisie, in
May, 1913, under the names Blue Moonstone and Moonstone claims. The
region is desert with rough lava-capped hills and washfilled valleys,
which drain northward. The chalcedony deposits are about 3,000 feet
above sea level.
White
to gray ash and conglomeratic tuff beds occupy the lower ground, with a
heavy flow of dark-red rhyolite overlying and capping the hills. This
rhyolite is vesicular in places and has been badly fractured and
crushed. Other lava flows occupy higher hills and mountains to the
south. In places a layer of gray perhte is exposed at the base of the
rhyolite, but the contact between the rhyolite and the underlying ash
beds is generally concealed by loose debris and talus. Blue chalcedony
has been found over parts of three claims in the lower portion of the
rhyolite or loose in the talus below. The best deposit is on the Blue
Moonstone claim on the north side of a small knob. The lower contact of
the rhyolite capping this knob is concealed bj talus, and, so far, the
blue chalcedony from this claim has been picked up from the talus where
it occurs in lumps of less than an ounce to several pounds weight
associated with the red rhyolite matrix. Il is probable that
prospecting above the talus bearing the chalcedonj would uncover the
matrix in place. The occurrence on the otkei claims is similar, but a
little of the chalcedony was found in place in the vesicular rhyolite.
The
blue chalcedony occurs as fillings in joints, fractures, and vesicular
cavities in the rhyolite forming veins and irregular masses Much of it
is very delicately banded, showing straight, curved, oi angularly bent
layers as in fortification agate. In some specimen!
