exceedingly improbable, however, that valuable deposits of platinum will be found in the parent rock.
Reports
were current during 1911 of a discovery of platinum metals at and near
the Granite-Poorman mining property, a few miles from Nelson. A
well-defined dike bearing these metals is said to have been traced for
several miles in the general direction of Fortynine Mile Creek and
across Kootenai River. A statement is made by E. Jacobs in the Canadian
Mining. Journal of September 1, 1911, that the rock containing the
platinum metals is serpentine and probably an altered peridotite. The
predominant metal is said to be palladium, though platinum and other
allied metals are also said to occur. Whether the find is of economic
importance is not certain. The existence of a new metal named canadium
has been reported in this serpentine rock, but the discovery has not
been confirmed.
The
occurrence of platinum in small quantities has been mentioned from
near Edmonton on the North Saskatchewan in Alberta and from Yukon River
at the mouth of Teslin and Lewes rivers in the Northwest Territory.
The
pre-Cambrian copper and nickel ores of Sudbury, Ontario, contain a
small percentage of platinum, palladium, rhodium, and ruhenium, some of
which is saved in refineries located in the United States.
IRIDIUM.
Uses.—The
properties of iridium are briefly indicated on a preceding page. Owing
to its unique qualities, iridium finds a fairly extensive use. Most of
the metal produced is probably used for the purpose of hardening
platinum, the percentage of iridium in the alloys ranging from 5 to 20
per cent. Up to 10 per cent of the alloys are ductile and malleable;
those containing from 10 to 20 per cent of iridium are hard and
difficult to work; where the alloy contains 30 per cent of iridium, it
is no longer attacked by aqua regia. Iridium is further used for
various scientific and technical purposes, such as standard weights,
pivots, contact points, and fountain-pen points. For certain
high-temperature experiments (above 1,600 C.) iridium is rolled in
sheets and welded into tubes. Pure iridium is difficult to work on
account of its brittleness. Iridium black, an oxide of the metal, is
highly valued as a pigment for decorating chinaware.
Production, imports, and prices.—The
source of iridium is the small amount contained in native platinum,
averaging perhaps 1.5 per cent, and, further, the small quantities of
iridosmine and native iridium recovered in the placers, regarding which
there is no reliable statistical information. Only small amounts of
iridium are contained in copper bullion. The world's production of pure
iridium is probably not more than 5,000 ounces a year, of which perhaps
about 500 ounces are recovered in the United States, mostly from
imported platinum sand and from copper ores and bullion.
According
to the Bureau of Statistics, 3,905 troy ounces of "iridium and iridium
in native combination with platinum metals," valued at $210,616, or
about $54 per troy ounce, were imported into the United States in 1911.
The price has been increasing rapidly, and in 1911 it ranged from $60
to $64 per ounce for pure metal.1
1 Eng. and Min. Jour., Jan. 6,1912, p. 4.
