Metallic element atomic number 78, atomic weight 195.09, mp 1772°C, specific gravity 21.45. First discovered by Western Science in South America by Ulloa in 1735, but had been used previously by the natives of Ecuador and Colombia. Finds are known particularly from La Tolita dating to the last centuries BC. The metal is malleable and ductile, however, its high melting point, well above the temperatures attainable in any medieval or earlier furnace, made it very difficult to consolidate the native metal. Hence, the early South American artefacts were of platinum sintered with gold.
In the 19th century AD an attempt was made to establish a Russian coinage based on platinum coming from the Urals. In this case, the metal was consolidated by sintering the metal at high temperature and pressure. This early attempt at powder metallurgy was soon abandoned due to technical difficulties.
Native platinum is usually alloyed with some iron. Sometimes there is sufficient iron present for the metal to be magnetic. Platinum was used in early scientific instruments since its coefficient of expansion is very similar to soda-lime glass.
Related terms: Platinum Group Elements, PGE inclusions