
Augelite: Gemstone Information
Colorless to yellowish, pale rose or pale blue crystals of augelite, A12 (PO4)(OH)3, have been fashioned. The monoclinic crystals have a tabular habit, a hardness of 5 and an SG near to 2.7. The RIs are 1.574, 1.576 and 1.588. The mineral is biaxial and optically positive with a birefringence of 0.014. The stones have a vitreous luster and show no luminescence under either form of UV.
Augelite is found at White Mountain, California, in Bolivia and in Spain. Material from California has RIs of 1.570–1.575 and 1.590–1.591, with a birefringence of 0.02. Large crystals have been found at the Champion mine, Mono County, California;. some have been fashioned but the source has been reported to be exhausted.