Ruthenium

Category: transition metal Atomic number: 44 Colour: silvery white Melting point: 2,334°C (4,233°F) Boiling point: 4,150°C (7,502°F) First identified: 1844

Ruthenium is a shiny, silvery metal that is most often found with other platinum metals in minerals such as pentlandite and pyroxinite. (The six platinum metals are found in a rectangular group in the periodic table, and have similar properties: they are ruthenium, rhodium, palladium, osmium, iridium and platinum.) It is mostly mined along with nickel or platinum, but it is a rare metal on planet Earth – only about twelve tons of it are extracted every year.

Ruthenium was probably first identified by the Polish chemist Jędrzej Śniadecki in South American platinum ores: in 1808 he claimed to have discovered a new metal, which he wanted to call vestium. But when others tried to repeat his work, the metal wasn’t found, so he gave up on the claim.

In 1825, the German chemist Gottfried Osann claimed to have found three new elements in platinum ores from the Urals: he named them pluranium, polinium and ruthenium. He was wrong about the first two, but Karl Karlovich Klaus at the University of Kazan confirmed the existence of ruthenium in the 1840s and kept Osann’s name (which was based on the archaic name Ruthenia, an area that includes modern Russia).

Ruthenium is used in alloys, to make platinum and palladium harder, and is also alloyed with these and other metals in (for instance) jewellery, electrical contacts, solar cells and chip resistors. The renowned fountain pen, the Parker 51, uses a gold nib tipped with 96 per cent ruthenium (alloyed with iridium).