Apachite
A copper silicate named for the Apache people of the area near Arizona's Christmas mine, where it was described in 1980.
Intro adapted from Wikipedia (CC BY-SA).
Apachite is an IMA-recognized mineral species in the silicate class, with the chemical formula Cu²⁺₉Si₁₀O₂₉·11H₂O.
It crystallizes in the monoclinic crystal system.
Key properties: Mohs hardness 2; specific gravity 2.8; Nonmetallic, silky luster; optically biaxial.
IMA symbol Apa, IMA status: approved, named in 1979.
A retrograde metamorphic or mesogene mineral, formed at the expense of a prograde calc-silicate and sulfide assemblage in tactites; typically in fractures or crackled zones cutting garnet-diopside rock.
It is found associated with Kinoite, gilalite, stringhamite, junitoite, clinohedrite, xonotlite, apophyllite, calcite, tobermorite.
The name refers to the Apache Indians who inhabit the region in Arizona, USA, where it occurs.