Show PLATINUM HAS MANY USES native platinum is really a natural alloy of platinum with iridium indium palladium or osmium of two or more of these metals and may contain also iron copper or gold according to the united states geological survey department of the interior it is usually found in small nuggets scales and rounded or irregular grains its color is steel gray the specific gravity of crude platinum ranges from 14 to 19 that is it is from 14 to 19 times as heavy as water A all ithe the platinum produced in the united states is mined in california and oregon owing to its great resistance to both heat and acids platinum is extensively used for making laboratory utensils platinum salts are employed in chemical analysis analyse s the metal has been used in making large concentration cent ration kettles for the manufacture of sulphuric acid but gold which is now cheaper has recently been substituted for it much platinum is used in photography dentistry and electric installation and especially in the manufacture of jewelry it is extensively used for making chains and especially for setting diamonds for it is said that it is not only more resistant than silver and harder than gold but that by its use the stones are set off better and appear larger than in any other kind of setting owing to the present high price of platinum there has been a recent great demand for substitutes for it at one time platinum was used in making incandescent lamps but in this use it is now almost entirely replaced by tungsten platinum triangles which were once used extensively in chemical laboratories for holding vessels over a flame have recently been successfully replaced by triangles made of an alloy of nickel and chromium nevertheless there are still so many industrial applications of platinum for which no substitutes can be found that it is not likely to become much cheaper cheapen the present extensive use of platinum in making jewelry is unfortunate for in this use other metals can be substituted for it and this fad has undoubtedly been one of the principal causes of the great increase in its price |