·noun A metallic element, intermediate in value between silver and gold, occurring native or alloyed with other metals, also as the platinum arsenide (sperrylite). It is heavy tin-white metal which is ductile and malleable, but very infusible, and characterized by its resistance to strong chemical reagents. It is used for crucibles, for stills for sulphuric acid, rarely for coin, and in the form of foil and wire for many purposes. Specific gravity 21.5. Atomic weight 194.3. Symbol Pt. Formerly called platina.