(L. Ruthenia, Russia) Berzelius and Osann in 1827 examined the residues left afterdissolving crude platinum from the Ural mountains in aqua regia. While Berzelius found nounusual metals, Osann thought he found three new metals, one of which he named ruthenium.In 1844 Klaus, generally recognized as the discoverer, showed that Osann's ruthenium oxidewas very impure and that it contained a new metal. Klaus obtained 6 g of ruthenium fromthe portion of crude platinum that is insoluble in aqua regia.

A member of the platinum group, ruthenium occurs native with other members of the groupin ores found in the Ural mountains and in North and South America. It is also found alongwith other platinum metals in small but commercial quantities in pentlandite of theSudbury, Ontario, nickel-mining region, and in pyroxinite deposits of South Africa.