Platinum production in 1914 Page 57



	352 MINERAL RESOURCES, 1914----PART I. tion, potassium platinic chloride (K₂PtCl₆), a yellow crystalline precipitate is formed when potassium chloride (KCl) is added; or ammonium platinic chloride (NH₄)₂PtCl₆, also yellow, when ammonium chloride (NH₄C1) is added. Both these precipitates are insoluble in alcohol but are soluble in water, and may be reduced by heating, so that sponge platinum is left. Iridosmine flakes are distinguished from platinum by their brittle-ness and by their giving off a pungent, unpleasant odor if highly heated. This odor is caused by the decomposition of osmium. The flakes will scratch glass, but can be scratched by quartz.