Tellurite (small yellowish crystals) with Tellurium (gray-black) in quartz. Tellurite is TeO2; tellurium is a native metal, Te. This is specimen comes from Sono — Photo: Shannon Heinle · CC0
Tellurium
A rare silver-white metalloid element (symbol Te, atomic number 52) — brittle, mildly toxic, occasionally found native.
Intro adapted from Wikipedia (CC BY-SA).
Tellurium is an IMA-recognized mineral species in the native element class, with the chemical formula Te.
It crystallizes in the hexagonal crystal system (space group P3_121).
Key properties: Mohs hardness 2–2.5; specific gravity 6.1–6.3; typically gray or white; Gray streak; Metallic luster.
IMA symbol Te, grandfathered status — known before the IMA’s founding, named in 1802.
Found in hydrothermal veins; may be of both primary and secondary origin; a sublimate in volcanic fumaroles.
It is found associated with Gold, sylvanite, empressite, altaite, pyrite, galena, alabandite, barite, quartz, carbonates.
Latin name for the earth, tellus.
Collections: Rare & Remarkable, Collector Favorites.