The chemical substance present in bones and teeth is:

Calcium and phosphorous combine as calcium phosphate

$left(mathrm{Ca}_{3}left(mathrm{PO}_{4} ight)_{2} ight)$ the hard material of bones and teeth. Seventy percent of bone consists of hydroxyapatite, a calcium phosphate mineral (known as bone mineral). Tooth enamel is composed of almost ninety percent hydroxyapatite.