Tantalum: a refractory metal with unique electrical, chemical, and physical properties that is used mostly as tantalum metal powder in the production of electronic components, mainly tantalum capacitors. Alloyed with other metals, tantalum is also used in making cemented carbide tools for metal working equipment, and in the production of superalloys for jet engine components. Australia, Brazil, Canada, Congo (Kinshasa), Ethiopia, and Rwanda are leading tantalum ore producers.