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VOLCANIC ASH.
Volcanic ash is a finely comminuted substance ejected by
volcanos, similar in composition to pumice. In Nebraska
and other western states of the United States and in the western
part of Canada deposits of this are found extending over large
areas and many feet in thickness. In many cases it is impure,
being mixed with sand, silt, clay, etc., while in others the beds
are very pure, white, and made up of decidedly angular grains
fairly uniform in size. 1
There is no record of any use having been made of the
Canadian material except for local consumption, but the de
posits of Nebraska have been extensively exploited.
At one time the name geyserite was incorrectly applied to
this material. It is now generally spoken of as volcanic ash,
volcanic dust or native pumice. For trade purposes other names
have been adopted, such as diamond polish and gibson grit.
Though often occurring in a loose earthy state, volcanic
ash is found also in a somewhat compact form, necessitating
passing it between rolls to break up the lumps.
In many cases, where exact uniformity of size of grain is
not demanded, the crude material, without any sifting or bolting,
is found to be satisfactory.
USES.
The principal uses of volanic ash are for the making of
scouring soap and soap powder, and metal polishes.
PRICES.
The price of the crude material for soap making purposes
ranges from $6 to $20 per ton, the average price being $14.
1 See “Notes on Deposits of Pumice/' p. 623, Mineral Resources of the United States,
part II, 1907, and “Volcanic Dust and its Present Production in Nebraska," page 828, Min
eral Industry, 1907.