What is "tricalcium phosphate"

Tricalcium phosphate (sometimes abbreviated TCP) is a calcium salt of phosphoric acid with the chemical formula Ca(PO). It is also known as tribasic calcium phosphate and bone phosphate of lime (BPL). Calcium phosphate is one of the main combustion products of bone (see bone ash). Calcium phosphate is also commonly derived from inorganic sources such as mineral rock.

It has three crystalline polymorphs α, α' and β. The α and α' states are formed at high temperatures. As rock, it is found in Whitlockite.