Louderback, G. D. "Benitoite, Its Paragenesis and Mode of Occurrence."
University of California Publications.
Page 333
particular notice of minerals and veins occurring in similar
geologic surroundings without seeing either of the more
characteristic minerals of this particular deposit. And it is not
because these minerals are difficult to see, for on the contrary
they are striking in appearance. They do not occur as
microscopic forms, but always in distinctly visible crystals
commonly of fairly good size. It would appear reasonable to
conclude that the minerals have not been simply overlooked, but
that they are really very restricted in their occurrence and are due
to a special and unusual set of conditionsÑa peculiar variation,
as the writer believes, of a type of geologic activity of rather
general occurrence along the Coast Ranges. The locality and
general geological surroundings therefore assume considerable
interest.
THE LOCALITY.
The only locality of benitoite known at present lies in San
Benito County, California, near the Fresno County line, on a
short tributary of the San Benito River which joins the latter
near its source. It is on the west side of the Diablo Range and
not far from its summit line, and about twenty-five miles in a
straight line (probably thirty-five miles by road) north of
Coalinga, where the mining company that owns and works the
property has its headquarters and from which it ships its
supplies. [2] Its geographical position is represented on the
index map, plate 27. The mine is
located on
section 25, township 18 south, range 12 east, Mount Diablo base and
meridian.
NOTES:
[2] It has been found very difficult to determine just who is the discoverer
of this interesting deposit. Different individuals have laid claim to this title
and a comparison of their various accounts shows that the ambition to be so
called has led to misrepresentations of the facts. As the writer has already
given names in his preliminary report and has found that the original
accounts given him are not entirely correct, he feels that a further statement
is due. Mr. J. M. Couch, a prospector of Coalinga, grubstaked by Mr.
Dallas, had in December found some deposits that seemed to need further
examination, and Mr. Dallas induced Mr. L. B. Hawkins of Los Angeles to
accompany Couch into the mountains for that purpose. While out to
examine some copper prospects they happened on the benitoite deposit and
each claims to be responsible for the discovery. Having no idea of the nature
of the material, they took some back to town for further enlightenment. At
first the idea, expressed by some ''expert" in Los Angeles, prevailed that the
material was volcanic glass and of no value. Later some stones were cut in
San Francisco, the lapidary believing that they were sapphires, and for some
time the property was known as the Sapphire Mine.
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