1) Calcium mineral 
Brushite is a phosphate mineral with the chemical formula {chemical formula|Ca||H||PO4||·2||H2O}. It forms colorless to pale yellow monoclinic prismatic crystals and as powdery or earthy masses. It is the phosphate analogue of the arsenate pharmacolite and the sulfate gypsum. ==Discovery and occurrence== Brushite was first described in 1865 for a...
• (n.) A white or gray crystalline mineral consisting of the acid phosphate of calcium.
rare mineral, a hydrated calcium phosphate (CaHPO42H2O), that forms colourless to pale-yellow, transparent to translucent efflorescences or tiny ...
Brush'ite noun [ From George J. Brush , an American mineralogist.] (Min.) A white or gray crystalline mineral consisting of the acid phosphate of calcium. 
Type: Term Pronunciation: brŭsh′īt Definitions: 1. A naturally occurring acid calcium phosphate occasionally found in dental calculus and renal calculi.
Brushite, named after the American mineralogist, George J Brush, is a white or grey crystalline mineral consisting of the acid phosphate of calcium.
Calcium orthophosphate