Batagayite
Batagayite is an IMA-recognized mineral species in the phosphate class, with the chemical formula CaZn₂(Zn,Cu)₆(PO₄)₄[PO₃(OH)]₃·12H₂O.
It crystallizes in the monoclinic crystal system (space group P2_1).
Key properties: Mohs hardness 3; specific gravity 2.9; White streak; Vitreous luster; optically biaxial.
IMA symbol Btg, IMA status: approved, named in 2017.
A secondary low-temperature mineral produced through alteration of primary minerals (copper and fluorapatite) in a quartz-phosphate mass ~5 m in diameter within greisenized cassiterite- bearing granodiorite.
It is found associated with Copper, arsenolite, tobermorite, epifanovite, libethenite, Na-analogue of batagayite, Mg-analogue of hopeite, pseudomalachite, sampleite, fluorapatite, quartz.
The name refers to Batagay (administrative center of the Verhoyansk ulus of the Sakha Republic, Russia), ~50 km from the deposit that produced the first specimens.