Ch. 2: Platinum in 1883/84

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	PLATINUM.	577

	of the Chaudiere river in Quebec. It has been noticed lately in a quartz vein impregnated with gold-bearing iron pyrites, which was struck when deepening the shaft of the Queen of Beauty Gold Mining Company's mine, Thames gold district, New Zealand. The interest in this deposit lies in the fact of the extreme rarity of platinum ores in place. Character of the ore.—Platinum " ore," as it is called, contains all the metals of this group, together with iron, copper, titanic iron ore, etc. It is sometimes, though seldom, found crystallized in cubes and octo-hedrous, but more usually in rounded or flattened grains or "sand" having a metallic luster; occasionally in large nuggets. The ore is very rarely found in place, but mixed with placer gold sands. The specimens containing the largest proportion of platinum have been found in Brazil. The following are analyses of platinum ores made, by Deville and Debray. (a) California ore sometimes yields the refiner only 50 per cent, of its weight in pure platinum.



	The substance termed osmiridium (iridosmine) is an alloy of osmium and iridium, which is separated by its insolubility in nitro-hydrochlorie acid. The sand mentioned contains quartz, chrome-iron ore, hyacinth,, spinel, and titanic iron. Production.—As early as twenty-five years ago the miners of California, finding small quantities of platinum sand in their sluices with the gold, were induced to collect and save it, under the impression that it commanded a higher price than was actually the case. Hence, during the first few years of placer mining in the State several hundred ounces of platinum, alloyed and mixed with the other associate metals,, were annually sold in San Francisco. Latterly, however, with the decrease in hydraulic mining, the amount has been much less, reaching not more than 100 or 200 ounces per annum. For this platinum sand 75 cents per troy ounce is paid, the purchaser (there is but one at present at San Francisco) shipping it to London. No attempt has been a "Annales tie Chimie et de Physique," third series, Vol. 56, page 449. 2 M B-------37

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