Fergus County argus. [volume] (Lewistown, Mont.) 1886-1946, 1901-05-29
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:Hmong the Miners :
DEVOTED TO THE LARGE AND SMALL :
NEWS OF THE MINING CAMPS .
OF FERGUS COUNTY. .

OF FERGUS COUNTY

600 feet, having a depth at the face OF
at least 200 feet.
The vein Mt the surface, and some
times To n depth OF fifty feet, is much
dccomposed, and the hydraulic force
is sufficient to work it for that depth,
but In the tunnel just mentioned the
vein-stuff has attained to a much
greaterdegree OF hardness and the Or
binary system of mining in vogue In
quartz mines Is used in theextraction.
The body OF the vein Is clearly n
bosic igneous flow, somewhat brecci-
ated near the surface and having
much the appearance OF the mlcaceous
schists common to several OF the
mountain ranges ofthis region. Near
the surface the vein presents many
c%olors, with red, yellow and brown
much In evidence, but with depth
these give way to a light blue and
green or n dark grey, with the latter
color predomlnating. A very fine
section of the vein IL seen in the face
Of the blue Diamond cut, which IL
about thirty-five feet high and shows
all the gradatiOns OF thcmagma from
the surface to the depth where the
hard rock II encountered.
In the most easterly working the
vein has been tapped at a point very
little above the level Of the Judith
river valley, and it appears that n
new formation has been invaded here,
az the walls exposed in the cut are Of
Il soft, shaley material, apparently
much different from the hard lines
higher up the hill. And here the mat
riX of the vein has undergone some
change, too; the varied colorlngs seen
In the workings %aboveare absent and
the entire body strongly resembles
the ordinary basalt. but the value In
gems is equally as great here as else
where.
On the American Gem Mining COM
pany's property the vein matter is
all extracted as il ore | n quartz mines.
These mines were recently bonded by
! a syndicate for $4,000 and although
tie company has been in active op-
Grafton but ten months several hun
dred feet Of development work has
been done on their properties.
Near Yogo creek. on the east side,
n great lime cliff rises abruptly from
the valley to a heightb Of 400 feet, and
in the face OF this elf can he seen the
walls marking the width Of the vein
where il has eroded from between the
harder formations composing the
walls. Into this cliff ii tunnel has
driven from the valley bottom at u
depth OF nearly 100 feet, aud the rein
is strong and well defined at this
depth.
The method Of extracting the sap
phlres from the magma Is much SINH
lar to that used by placer miners in
sluicing for gold. The sluice boxes
are fitted with Hungarian rifles, as
in placer mining, but it Is necessary
to exercise more care in setting them,
as the specific gravity Of the sapphire
Is much less than that OF gold and
with the boxes set at too great a
pitch" they would pass over the riff
nes and he lost. When first extracted
the magma IL passed over grizzly"
(screen) and the finer parts pass at
once into the sluices. The coarser,
harder material Is thrown into the
dump, where after exposure to the
elements ii finally disintegrates and
Is then passed into the slulces. The
process OF dlsintegratiOn occupies
from one month to n year, according
to the hardness and tenacity OF the
magma. Superintendent Sweeney
OF the American company assists the
elements in the disintegration Of his
dumps by turning u flow Of wateron
them occasionally. andb " this means
the hardest Of the vein matter Is
ready to pass through the sluices in
two months.
For cleaning up an ordinary rocker
Is used, with three screens ofas many
sizes, through which the "pay dirt
Is passed. When the pay dirt" has
been worked down as closely as pos
sible In the rocker ii ia panned in one