- The chief inorganic component of the calcified structures in the human body, such as bones and teeth, is Hydroxyapatite.
- Hydroxyapatite is a naturally occurring mineral form of calcium phosphate, with the chemical formula Ca₁₀(PO₄)₆(OH)₂.
- It provides the necessary rigidity and strength to the skeletal system by forming a crystalline matrix that integrates with the organic collagen framework.

- While calcium carbonate is an important mineral in other biological contexts (such as shells of marine organisms), it is not the primary mineral in human bones and teeth.
- Magnesium phosphate and fluorapatite are related compounds but occur in much smaller amounts or are modifications of hydroxyapatite.
- For example, fluorapatite is formed when fluoride ions replace hydroxyl groups in hydroxyapatite, which can contribute to tooth enamel resistance but is not the original main mineral.

In summary:
- The main mineral component of bones and teeth = Hydroxyapatite
- Composed primarily of calcium and phosphate ions
- Provides mechanical strength and structural support
- Forms a crystalline matrix integrated with collagen

Reference: Gray’s Anatomy, 41st Edition, Volume 1, Chapter 5: Bone Structure and Function