Custer weekly chronicle. [volume] (Custer City, S.D.) 1890-1931, 1900-01-20
THE LATEST DISCOVERY.
A Forty Foot Vertical Vein Of Onyx and
Kaolin, With Ten Feet of Min
eraf near Custer.


Kaolin, With Ten Feet of Min
erai near Custer.
It has often been remarked by the
most eminent geologists and mineral
ogists who have visited the Black Hills
that this region exhibited the greatest
variety and abundance not only Of min
eral in veins, but also non-metallic
stones of commercial value. This time
it was the good fortune Of Messrs. W..
r. Bond, 6 w. Book and F. NJ. Hughes
to discover one of the most remarkable
veins which have thus far been opened
in this section of country, which is al
ready famous for its great variety Of
mineral and stone. They were pros
pecting on the southern slope of the
Harvey Peak, about FIVE miles east Of
Custer, where they fornd ledge OF
what appeared to be a variegated marble
and onyx, with a three foot strata Of
ore, heavy with variety Of mineral,
the constituents and value of which
have not as yet been analyzed or ascer-
tanned.
The country rock here 10 granite Of
the coarsely chrystalline variety, which
composes the whole of the Harvey
range, while the vein is inclosed be-
tween walls of feldspar and
mica schist. In cross-cutting the vein
zt the surface they found on the foot
wall feet of fine grained, blush
gray granite quite solid
and free from fAws. Overlaying this a
granulated mass Of partly chrystalIized
material Of about 10 feet in width.
Then comes 10 foot etrata of what ap.
pears a white and variegated marble,
which is also susceptible of very fine
polish. Then comes vein Of highly
mineralized rock, carrying manganese
and other minerals, which will need to
be analysed to determine their value.
Next comes a foot Of variety Of onyx
or what might be more properly des-
cribed as agate, although it is similar
in appearance to the finest Mexica n
onyx. This stone is harder than the
rest and far the most beautiful, as it
takes an exquisite polish, and has all
the colors of the rainbow.
Lieing next this is a l5 foot strata of
"kaolin," or China clay" which has
very much the appearance of white tale.
But we have been told that it has been
expert pronounced by an
in clays as very fine variety OF
kaolin, which is decomposed feldspar'
or "silicate Of alluriina." 1t is extern
sivelv nsed in the manufacture of fine
porcelain, and should be considered in
itself a valuable acquisition to our dis
trict, rs no such body of pure kaolin
has ever been found in America, at least
it is not on record in any of the geolo
gical reports. 1t is said that this clay
can be mined and taken direct to the
factory without washing, and that they
work it in this manner in different
places in Europe. notably in st. Yriux
in France. This clay is at present i'm
ported into this country from different
parts of Europe, the United States year
ly. consuming about seventy-five thous
and tons. 1t would seem that the
necessity Of ofimporting this material into
the United States would now be obyiat-
ed, as this nine is on scale sufficiently
grand to supply all tho demands of this
country, "and then some." We shall
give further report of this valuable
discovery, as development work goes
on, and the mineral has been more
thoroughly tested.