Tricalcium phosphate (sometimes abbreviated TCP) is a calcium salt of phosphoric acid with the chemical formula Ca3(PO4)2. It is also known as tribasic calcium phosphate and bone phosphate of lime (BPL). It is a white solid of low solubility. Most commercial samples of “tricalcium phosphate” are in fact hydroxyapatite. It exists as three crystalline polymorphs α, α’, and β. The α and α’ states are stable at high temperatures. As mineral, it is found in Whitlockite.