Vernon County censor. [volume] (Viroqua, Wis.) 1865-1955, 1908-10-14

Stecrett, of the United States geologi-
cal survey, whose statistical report on
the precious stones OF this country
as just been published by the survey
as an advance chapter from Mineral
Resources of the United States. Cal
andeT Year 1907 Two large COM
panies operated mines containing blue
sapphire in its original matrix. and
two other large companies and smaller
or individual producers worked auri-
ferrous placer deposits containing VA
.colored spphires. The blue sapphire
in matrix VIZ worked in the judith
river region. in Fo-s,s County. az
points about II and Is miles west
southwest of Utica; the placer de-
posts were worked at the head q
Dry Cottonwood creek, in Deerlodge
county. The auriferous placer de-
posits along Missouri river below
Helena, once so extensively worked,
also yielded a few stones during 1907
the blue sapphires of Fergus county,
often called Yogo sapphires, range
in size from minute crystals up 70
those of 4 or 5 carats. Rarely crys-
tails of 8 or 10 carats are founr. but
the greater number weigh under 3
carats. A large quantity of small
saphlres. cl&ssed as culls. is also OBJ
/ tanned. This material is in great de-
mand for watch jewels the fiatrened
form of many of the crystals render
ing them specially suitable for this
purpose. In color the Yogo sapphires
range from light blue to the rich
'cornflower" blue characteristic OF
the oriental sapphire. They make
beautiful gems and are highly priced
, for their color and brilliancy. PROP.
ably over 80 per cent Of the sapphire
is of good blue color and OF gen,
quality Occasionally purplish gems
are found.
The auriferous placer eposits on
Dry Cottonwood creek are located at
an elevation OF 5000 feet, nearly I.5O0
feet above the valley of DeerIodge
river, 10 which the creek is tributary.
The gravels in the gulches are from
10 to ID feet thick and the beds are
from 40 to 100 feet wide. The gold
carried by the gravels and recovered
from the concentrates is mostly fine
although nuggets worth several dol
lars are said to have been found. 1t
is claimed that the value of the gold
recovered is sufficient to pay operat
ing expenses. The larger part Of the
sapphires of this locality can be used
for mechanical purposes only. bat
some or The crystals are suitable in
size, color, and quality for cutting II
these sapPhires are deep and light
aquamarine and pale yellowish green.
Other cOlors are clear and smoky
blue, light and dark topaz yellow,
straw yellowish green, and light ana
dark pink Some stones are nearly
ruby red, lilac, and pale amethystine
and some are colorless. 1t is not un.
usual to find aquamarine colored
stones with a pink spot in the center
"a combination trat furnishes an at
tractive gem when cut The deem
pink sapphires are particularly rich
and beautiful under artificial light.
even when not very attractive in ma
tural light.
A brief account of the Montana sap
phire mines is given by Douglas B.
Sterrett in paper on the production
OF precious stones published by the
United States Geological survey as
an advance chapter from Mineral
Resources of the United States, Cal
endar Year 1907" Copies Of this pa
per may be obtained by applying to
the director of the survey at Wash
ington.