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PLATINUM AND ALLIED METALS.
997
Possibility of new discoveries in California and Oregon.—It seems very unlikely that any important discoveries of platinum sand will be made in the well-prospected gold-bearing districts. The presence of platinum along the whole coast of California shows that it has been transported from the adjacent land area and, as serpentine areas occur extensively in the coast ranges, it is well possible that within this mountainous district localities may yet be found which will prove richer in platinum than the occurrences thus far known.
The coast ranges have been prospected but little, as the larger part of them is entirely barren of gold-bearing deposits, and it may be well worth while to examine these districts by panning the gravels in order to ascertain whether any of these serpentine and peridotite areas may not contain more platinum than those occurring in the well-prospected gold-bearing areas. Although probably all peri-dotites and some pyroxenites contain a little platinum, yet it is evident that only in few places in the world does the metal occur in economically important quantities.
Other States.—The literature contains frequent mention of platinum in gold-bearing gravels in the States outside of California and Oregon. It has been reported from Arizona. In Colorado it is reported from Buena Vista in Chaffee County, Aspen in Pitkin County, Liberty in Saguache County, and Tellunde in San Miguel County. In Idaho it is reported from the Payette River and Snake River sands, also at Rocky Bar, in Elmore County, at Elk City district in Idaho County, on North Fork of Clearwater River in Idaho County, and at Pierce City in Shoshone County. In Montana, according to D. T. Day, it is found in concentrates from Princeton in Granite County. In north­eastern Oregon it occurs at Durkee in Baker County, and also, it is stated, near Sumpter; it is also mentioned as occurring in sands at Foster in Lynn County, at La Grande in Union County, and at Hills-boro in Washington County. In Utah it is reported at Hite in Gar­field County. In Washington it is found on the beaches in Clallam County, and on Sand Island in Pacific County.
The occurrence of platinum in copper ores, mostly of pre-Cambrian age, in Wyoming and Nevada has already been mentioned. In these ores there is usually more palladium than platinum. Copper and gold bullion generally contains a small quantity of platinum metals, which is saved in some refining processes.
In the Eastern States platinum is rare but has been reported from Lumpkin County, Ga., from Maryland near Baltimore, and from Rutherford County, N. C. A nugget of platinum weighing 104
g rams was once found in the glacial drift near Plattsburg, N. Y. It was intergrown with chromite.
FOREIGN COUNTRIES.
Central America, West Indies, and Mexico.—Platinum sands are reported from Honduras and from the island of Santo Domingo. In Mexico platinum is evidently extremely rare, and no reliable data of its occurrence are available.
Brazil.—Platinum was observed at an early date in the gold washings of Minas Geraes, but very little, if any, of the metal has actually been recovered.
Borneo.—Platinum was discovered in 1831 in the gold washings of southeastern Borneo in gravels derived from serpentine, diorite,