Aheylite , Cassiterite Locality: Huanuni mine, Huanuni , Dalence Province, Oruro Department , Bolivia ( Locality at mindat.org ) Size: 3.5 x 2.3 x 0.8 cm. Pastel blue, translucent, spheres to .2 cm across of the very rare phosphate, aheylite, are perched on very lustrous crystals of cassiterite, to .6 cm across, along with colorless, quartz crystals. Aheylite, a hydrated, iron, aluminum, phosphate. Ex. Brian Kosnar. — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Aheylite
Aheylite is a rare phosphate mineral with formula (Fe2+Zn)Al6[(OH)4|(PO4)2]2·4(H2O). It occurs as pale blue to pale green triclinic crystal masses. Aheylite was made the newest member of the turquoise group in 1984 by International Mineralogical Association Commission on New Minerals and Mineral Names.
Intro adapted from Wikipedia (CC BY-SA).
Aheylite is an IMA-recognized mineral species in the phosphate class, with the chemical formula Fe²⁺Al₆(PO₄)₄(OH)₈·4H₂O.
It crystallizes in the triclinic crystal system (space group P-1). It is a member of the Turquoise structural group.
Key properties: Mohs hardness 5–5.5; specific gravity 2.84; White streak; Porcelaneous to subvitreous luster; optically biaxial.
IMA symbol Ahe, IMA status: approved, named in 1984.
A late stage hydrothermal mineral in a base-metal-tin deposit (Huanuni mine, Bolivia).
It is found associated with Variscite, sphalerite, vivianite, wavellite, cassiterite, pyrite, quartz (Huanuni mine, Bolivia).
The mineral was named to honor Allen V. Heyl (1918–), economic geologist, U.S. Geological Survey.