varieties.
Often, near the chrysoprase veins, the serpentine is badly decomposed
and is stained with nickel. The chrysoprase is found in veinlets and
veins from one-fourth inch to 8 or 10 inches thick, cutting through the
serpentine. The color of the chrysoprase varies considerably in
different veins and in different parts of the same vein. In some cases
the middle portion has a fine green color of the valuable shade, while
in others gem material may occupy any portion in the vein. The greater
part of the larger veins is not of good gem quality, and the best
material is confined chiefly to the thin veins or the thinner portions
of the veins.
The
main workings are on the south side of the hill. They consist of two
shallow open cuts, extending probably 20 to 25 feet into the hillside,
where they meet, and about 15 feet deep in the deepest part, with other
smaller openings. Much good chrysoprase is obtained as float by plowing
up and harrowing the land lower down on the gentler slopes of the hill.
In this way the loose rocks are turned up, and, after exposure to the
rain, the good chrysoprase is readily picked out. The operation is then
repeated and another crop gathered.
It
is reported that from this mine about 3 tons of material have been
shipped from which it was said about 300 pounds of gems could be cut.
That portion unsuitable for gem purposes is to be shipped to Germany
for cutting into slabs for mosaics. Large masses of silicified
serpentine, weighing several hundred pounds, with light-colored
chrysoprase veins an inch or less thick are to be shipped also. In a
fire on the property during the year, nearly 4 tons of chrysoprase
ready for shipment were burned and practically destroj'ed. Much of it
lost its color and was so badly cracked by the heat as to be valueless.
On
the north side of the hill opal veins have also been found in a
decomposed serpentine. The veins are all small, ranging in thickness
from an inch down. In some cases the opal has a green color, like that
of the chrysoprase, and is called chrysopal.
The
same company has operated chrysoprase mines at Venice Hill, about 10
miles east of Visalia and near Exeter. These deposits are about 35
miles and 28 miles respectively north-northwest of the Deer Creek
deposit. Small deposits are also reported on White River 25 miles south
of Porterville, but their value is, so far, doubtful. Beautiful
specimens of chrysopal are found in a serpentine hilltop just east of
Piano, about 1-1/2 or 2 miles south of Porterville, but it is not known to have been used commercially.
DIAMOND.
PROSPECTING IN THE UNITED STATES.
Authentic
reports of the finding of diamonds in Arkansas during 1906 were
received at this office, and there were rumors of diamond discoveries
in the localities mentioned in the following paragraphs. A report on
the Arkansas discoveries is appended to this paper.
California.—The
discovery of what has been called a "diamond pipe" near Oroville, Cal.,
by Mr. M. J. Cooney, has caused considerable comment in various papers
both East and West. The deposit in question was found along the west
bank of Feather River, about a mile north of Oroville, in ground from
which 20 to 60 feet of alluvium had been washed off during hydraulic
gold-mining operations. The
