Which of the following is the chief mineral of bone?
Calcium oxalate
Hydroxyapatite
Calcium carbonate
Calcite
The inorganic or mineral component is mainly crystalline hydroxyapatite--Ca10(PO4)6(OH)2--along with sodium, magnesium, carbonate, and fluoride; approximately 99% of the body's calcium is contained in bone. Hydroxyapatite confers on bone the strength and resilience required by its physiologic roles. Type I collagen is the major protein, comprising 90-95% of the organic material. Ref: Keeley F.W., Murray R.K. (2011). Chapter 48. The Extracellular Matrix. In D.A. Bender, K.M. Botham, P.A. Weil, P.J. Kennelly, R.K. Murray, V.W. Rodwell (Eds), Harper's Illustrated Biochemistry, 29e.