Yellow brown crystals of the very rare tellurite-tellurate mineral yecoraite from the type locality in Yécora, Mexico (San Martín de Porres Mine, Yécora, Sonora, Mexico). Associated mineral is metallic tetradymite. — Photo: David Hospital · CC BY-SA 4.0
Yecoraite
Yecoraite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Fe³⁺₃Bi₅O₉(Te⁴⁺O₃)(Te⁶⁺O₄)₂·9H₂O.
Key properties: Mohs hardness 3; specific gravity 5.59; Pitchy luster; optically uniaxial.
IMA symbol Yec, IMA status: approved, named in 1983.
Found in fractures in a quartz vein emplaced in quartz monzonite, an oxidation product of tetradymite and pyrite.
It is found associated with Tetradymite, pyrite, chalcopyrite, quartz, iron oxides.
The name refers to the proximity of its first occurrence to Yecora, Sonora, Mexico.