calcium phosphate

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A colorless deliquescent powder, Ca(H₂PO₄)₂, used in baking powders, as a plant food, as a plastic stabilizer, and in glass.
2. n. A white crystalline powder, CaHPO₄, used as an animal food, as a plastic stabilizer, and in glass and toothpaste.
3. n. A white amorphous powder, Ca₃(PO₄)₂, used in ceramics, rubber, fertilizers, and plastic stabilizers and as a food supplement.

Wiktionary

1. n. inorganic chemistry The calcium salt or phosphoric acid, Ca3(PO4)2, or of several related acids; it is the main mineral of bone

WordNet 3.0

1. n. a phosphate of calcium; a main constituent of animal bones