Platinum..

History

Platinum occurs naturally in the alluvial sands of various rivers, though there is little evidence of its use by ancient peoples.

Characteristics

As a pure metal, platinum is silvery-white in appearance, lustrous, ductile, and malleable.[3] It does not oxidize at any temperature, although it is corroded by halogens, cyanides, sulfur, and caustic alkalis. Platinum is insoluble in hydrochloric and nitric acid, but dissolves in aqua regia to form chloroplatinic acid, H2PtCl6.[4] Platinum's wear- and tarnish-resistance characteristics are well suited for making fine jewelry. Platinum is more precious than gold or silver. Platinum possesses high resistance to chemical attack, excellent high-temperature characteristics, and stable electrical properties. All of these properties have been exploited for industrial applications.

Occurrence

Platinum exists in relatively higher abundances on the Moon and in meteorites. Correspondingly, platinum is found in slightly higher abundances at sites of bolide impact on the Earth that are associated with resulting post-impact volcanism, and can be mined economically; the Sudbury Basin is one such example. Precious metal Platinum is a precious metal commodity; its bullion has the ISO currency code of XPT. Coins, bars, and ingots are traded or collected. Platinum finds use in jewelry, usually as a 90-95% alloy.

Symbol of prestige

An assortment of native platinum nuggets Platinum's rarity as a metal has caused advertisers to associate it with exclusivity and wealth. "Platinum" debit cards have greater privileges than do "gold" ones. "Platinum awards" are the second highest possible, ranking above "gold", "silver" and "bronze", but below Diamond.