White, odorless, tasteless powder. Is stable in air. Practically insoluble in water.
The second acidity of phosphoric acid corresponds to a weak acid. The neutralization of two acidities of phosphoric acid with calcium hydroxide leads to dicalcium phosphates. Two crystalline forms exist: DCPD (also called Brushite by mineralogists) and DCPA (also called Monetite). DCPA is the anhydrous form of DCPD. It is less soluble than DCPD due to the absence of water inclusions. DCPA, like DCPD, can be crystallized from aqueous solutions, but at 100 ◦C. Unlike DCPD, DCPA occurs in neither normal nor pathological calcifications. It is used in calcium phosphate cements, sources of calcium and phosphate in nutritional supplements such as breakfast cereals, and toothpaste components.