Ruthenium is generally found in ores with the other platinum group metals in the Ural Mountains and in North and South America.

Small but commercially important quantities are also found in pentlandite extracted from Sudbury, Ontario, and in pyroxenite deposits in South Africa.

A ruthenium–molybdenum alloy is known to be superconductive at temperatures below 10.6 K.[11] Ruthenium is the only 4d transition metal that can assume the group oxidation state +8, and even then it is less stable there than the heavier congener osmium: this is the first group from the left of the table where the second and third-row transition metals display notable differences in chemical behavior.

[20] It is generally found in ores with the other platinum group metals in the Ural Mountains and in North and South America.

Small but commercially important quantities are also found in pentlandite extracted from Sudbury, Ontario, Canada, and in pyroxenite deposits in South Africa.

The native form of ruthenium is a very rare mineral (Ir replaces part of Ru in its structure).

An unusual ruthenium deposit can also be found at the natural nuclear fission reactor that was active in Oklo, Gabon, some two billion years ago.

Indeed, the isotope ratio of ruthenium found there was one of several ways used to confirm that a nuclear fission chain reaction had indeed occurred at that site in the geological past.

[24] The composition of the mined platinum group metal (PGM) mixtures varies widely, depending on the geochemical formation.

One representative method is fusion with sodium peroxide followed by dissolution in aqua regia, and solution in a mixture of chlorine with hydrochloric acid.

[27][28] Osmium (Os), ruthenium (Ru), rhodium (Rh), and iridium (Ir) are insoluble in aqua regia and readily precipitate, leaving the other metals in solution.

Exposing the 99Tc target to strong enough neutron radiation will eventually yield appreciable quantities of ruthenium, which can be chemically separated while consuming 99Tc.

The most prevalent precursor is ruthenium trichloride, a red solid that is poorly defined chemically but versatile synthetically.

[37] Unlike osmium tetroxide, ruthenium tetroxide is less stable, is strong enough as an oxidising agent to oxidise dilute hydrochloric acid and organic solvents like ethanol at room temperature, and is easily reduced to ruthenate (RuO2−4) in aqueous alkaline solutions; it decomposes to form the dioxide above 100 °C.

Like iron, ruthenium does not readily form oxoanions and prefers to achieve high coordination numbers with hydroxide ions instead.

It hydrolyzes violently upon contact with water and easily disproportionates to form a mixture of lower ruthenium fluorides, releasing fluorine gas.

[40] Ruthenium trichloride is a well-known compound, existing in a black α-form and a dark brown β-form: the trihydrate is red.

The colorless liquid ruthenium pentacarbonyl converts in the absence of CO pressure to the dark red solid triruthenium dodecacarbonyl.

Ruthenium trichloride reacts with carbon monoxide to give many derivatives including RuHCl(CO)(PPh3)3 and Ru(CO)2(PPh3)3 (Roper's complex).

[43] Platinum in alluvial sands of Russian rivers gave access to raw material for use in plates and medals and for the minting of ruble coins, starting in 1828.

It is possible that the Polish chemist Jędrzej Śniadecki isolated element 44 (which he called "vestium" after the asteroid Vesta discovered shortly before) from South American platinum ores in 1807.

[47][49] The name "ruthenium" was chosen by Osann because the analysed samples stemmed from the Ural Mountains in Russia.

[23] Because it hardens platinum and palladium alloys, ruthenium is used in electrical contacts, where a thin film is sufficient to achieve the desired durability.

[58] Ruthenium is also used in some advanced high-temperature single-crystal superalloys, with applications that include the turbines in jet engines.

[63] Ruthenium is a component of mixed-metal oxide (MMO) anodes used for cathodic protection of underground and submerged structures, and for electrolytic cells for such processes as generating chlorine from salt water.

[66] The beta-decaying isotope 106 of ruthenium is used in radiotherapy of eye tumors, mainly malignant melanomas of the uvea.

[68] Compared with platinum complexes, those of ruthenium show greater resistance to hydrolysis and more selective action on tumors.

[70] Copper can be directly electroplated onto ruthenium,[71] particular applications include barrier layers, transistor gates, and interconnects.

Chiral ruthenium complexes, introduced by Ryoji Noyori, are employed for the enantioselective hydrogenation of ketones, aldehydes, and imines.

[76] A typical catalyst is (cymene)Ru(S,S-TsDPEN):[77][78] A Nobel Prize in Chemistry was awarded in 2001 to Ryōji Noyori for contributions to the field of asymmetric hydrogenation.