Augelite is soft and brittle, unsuited for wear. However, the gems cut from rare transparent crystals are true collector items and are seen only in very complete collections.
The International Gem Society (IGS) has a list of businesses offering gemstone appraisal services.
|Crystallography||Monoclinic. Crystals tabular and thick; prismatic; acicular. Also massive.|
|Colors||White, yellowish, pale blue, pale rose.|
|Luster||Vitreous. Pearly on cleavage surfaces.|
|Cleavage||Perfect 1 direction, good 1 direction.|
|Stone Sizes||Most gems in existence form the California material are less than 1 carat up to about 3 carats. Larger stones are exceedingly rare in the case of what is already a rare mineral.|
Optics: α= 1.574; β = 1.576; γ = 1.588
White Mountain, California, material: α= 1.570; β = 1.574; γ = 1.590
Biaxial (+), 2V ~50°
Occurrence: Crystals from the Champion Mine, Mono County, California, reach a size of about one inch; this locality is now depleted. It furnished cuttable gem material. Masses occur at Keystone, South Dakota (nongem). Palermo Mine, New Hampshire. Potosi, Bolivia: In crystals. Sweden: massive Uganda.
Comments: Augelite is soft and brittle, unsuited for wear. However, the gems cut from rare transparent crystals are true collector items and are seen only in very complete collections.
Name: From a Greek word meaning Luster, because of the glassy appearance of the mineral.