Green crystal aggregates of the very rare Ba-ASl phosphate from the type and only known locality worldwide in Yukon (Hess River, Mayo District, Yukon, Canada). — Photo: David Hospital · CC BY-SA 4.0
Jagowerite
Jagowerite is an IMA-recognized mineral species in the phosphate class, with the chemical formula BaAl₂(PO₄)₂(OH)₂.
It crystallizes in the triclinic crystal system (space group P-1).
Key properties: Mohs hardness 4.5; specific gravity 4.01; Vitreous luster; optically biaxial.
IMA symbol Jgw, IMA status: approved, named in 1973.
Found in quartz veins filling tension fractures in carbonaceous argillite.
It is found associated with Pyrite, hinsdalite.
The mineral was named to honor John Arthur Gower (1921–1972), Professor of Mineralogy, University of British Columbia, Vancouver, Canada.