Ruthenium is a chemical element with the symbol Ru and atomic number 44. It is a hard, silvery-white metal that belongs to the transition metals and is classed with the platinum group metals. For a general introduction see this element overview, and for a simple reference to its atomic number see atomic data.

Physical and chemical characteristics

Ruthenium is notable for its high resistance to wear and corrosion and its ability to retain metallic luster. Chemically it shows several oxidation states, commonly +2, +3 and +4, and forms a variety of complex compounds. As a member of the transition metals, ruthenium participates in coordination chemistry and can act as a robust catalyst in oxidation and hydrogenation reactions. Its scarcity among metals is often noted in discussions of rare elements; see rarity and classification.

Occurrence and production

Ruthenium is not found as a primary ore on its own; it occurs as a minor component in some platinum-group mineral deposits and in alloys with platinum and osmium. Commercial extraction typically comes from processing of platinum and nickel ores: it is recovered as a byproduct during refining. Many descriptions of its geological context refer to platinum-group ores and primary recovery routes.

Uses and applications

Although produced in small quantities compared with common industrial metals, ruthenium has several important applications. It is used to harden platinum and palladium alloys, to improve wear resistance of electrical contacts, and as a constituent in certain high-performance catalysts. A typical note on industrial use points to its role in improving catalytic properties when added to other metals; for examples see catalyst alloys. In electronics thin layers of ruthenium are applied to contacts and in thick-film resistors because of their stability and conductivity.

History and notable facts

Ruthenium was identified in the early 19th century during studies of residues from platinum ore refining. It is named for the Latin name of Russia, where some of the earliest samples originated. As part of the platinum group, ruthenium has attracted attention for specialized uses rather than bulk applications, and its market and production remain closely tied to platinum and nickel refining industries; historical accounts often mention its discovery alongside other noble metals and the development of refining techniques.

Safety and distinctions

  • Ruthenium metal is generally regarded as having low chemical reactivity in bulk but certain ruthenium compounds can be toxic or irritant; standard handling precautions for heavy metals should be observed.
  • It is distinct from other platinum-group metals by its particular electronic properties and common oxidation states, which give it specialized catalytic roles.
  • Because it is produced as a byproduct, its supply is sensitive to activity in unrelated mining sectors; economic and technological shifts can influence availability.

For further reading and specific data pages, see platinum group context and the linked references above. Additional technical and industrial examples are available through specialized materials and chemistry sources linked here: element information, atomic summary, and transition metal resources.