Brown crystal aggregates of the very rare mineral carbonate-phosphate mineral bradleyite associated to white acicular loughlinite from Westvaco Mine, Green River Basin, Sweetwater County, Wyoming, United States of America. Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY 4.0
Bradleyite
Bradleyite is an IMA-recognized mineral species in the phosphate class, with the chemical formula Na₃Mg(PO₄)(CO₃).
It crystallizes in the monoclinic crystal system (space group P2_1/m). It is a member of the Bradleyite structural group.
Key properties: Vitreous luster; optically biaxial.
IMA symbol Bd, grandfathered status — known before the IMA’s founding, named in 1941.
A rare mineral found in oil shale in the Green River formation.
It is found associated with Shortite, clay minerals, trona, pirssonite, 'northupite, gaylussite, alstonite, dolomite, quartz.
The mineral was named to honor Dr. Wilmot Hyde Bradley (1899-1979), geologist, U.S. Geological Survey, who studied the Green River formation. Type Material: National Museum of Natural History.