Brown crystal of the very rare mineral zincospiroffite from the famous locality of Moctezuma (Bambolla Mine, Moctezuma, Sonora, Mexico), and the third known locality for the mineral worldwide. — Photo: David Hospital · CC BY-SA 4.0
Zincospiroffite
Zincospiroffite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Zn₂Te₃O₈.
It crystallizes in the monoclinic crystal system (space group C2/c).
Key properties: specific gravity 5.57; Dark green streak; Vitreous. Weak anisotropy, bireflectance and reflection pleochroism. R1-R2: (470 nm) 7.0-7.5, (546) 7.1-7.3 luster.
IMA symbol Zspf, IMA status: approved, named in 2002.
Found as a secondary mineral in an oxidized Te- and Au-bearing quartz vein.
It is found associated with Occurs as a rim on, or a replacement of, calaverite, contains blebs of gold, sphalerite.
As the zinc-dominant analogue of spiroffite.