A brittle metallic element usually found in combination with → gold and other → metals, used to → alloy stainless → steel and → lead, and, as bismuth telluride, in thermoelectric devices; symbol Te. → Atomic number 52; → atomic weight 127.60; → melting point 450°C; → boiling point 990°C; → specific gravity 6.24 at 20°C. It was discovered by the Roumanian mine director Franz Joseph Muller von Reichenstein in 1782 and overlooked for sixteen years until it was first isolated by German chemist Martin-Heinrich Klaproth in 1798. The Hungarian chemist Paul Kitaibel independently discovered tellurium in 1789, prior to Klaproth's work but after von Reichenstein.
From L. tellur-, from tellus "earth" + -ium a L. suffix occurring in the name of some chemical elements.