Platinum

A metallic element of atomic number 78 one of the noble metals classed with silver and gold as a precious metal occurring native or alloyed with other metals and also as the platinum arsenide sperrylite It is a heavy tin white metal which is ductile and malleable but very infusible melting point 1772deg C and characterized by its resistance to strong chemical reagents It is used for crucibles in laboratory operations as a catalyst in jewelry for stills for sulphuric acid rarely for coin and in the form of foil and wire for many purposes Specific gravity 215 Atomic weight 1951 Symbol Pt Formerly called platina