| Apatite | |
|---|---|
 Apatite from Perth, Ontario, Canada. Specimen is approximately 4 inches (10 centimeters) across. | |
| Uses | Manufacture of fertilizer - it is a source of phosphorus. Occasionally used as a gemstone. Apatite also serves as an index mineral of Mohs hardness scale with a hardness of five. |
| Color | green, brown, blue, yellow, violet, colorless |
| Streak | white |
| Luster | vitreous to subresinous |
| Diaphaneity | transparent to translucent |
| Cleavage | poor |
| Luster | vitreous to subresinous |
| Hardness | 5 |
| Specific Gravity | 3.1 - 3.2 |
| Distinguishing Characteristics | easy to recognize by color, crystal form, and hardness, can be scratched with a steel knife blade |
| Crystal System | hexagonal |
| Chemical Classification | phosphate |
| Chemical Composition | a variety of calcium phosphates: fluorapatite: Ca5(PO4)3F, hydroxylapatite: Ca5(PO4)3(OH), chlorapatite: Ca5(PO4)3Cl, carbonate-rich apatite/francolite: Ca5(PO4,CO3)3(F,O) |
Apatite is a group of phosphate minerals which includes: fluorapatite, chlorapatite, hydroxylapatite, carbonate-rich apatite and francolite. The term "apatite" is often used for fluorapatite, the most common of these minerals. Apatite is found in igneous, metamorphic and sedimentary rocks. The most extensive deposits are the sedimentary "phosphate rocks", which are mined to produce phosphate fertilizer.
Apatite Crystal from Perth, Ontario, Canada. Specimen is approximately 2 inches (5 centimeters) across.
Apatite Crystal from Perth, Ontario, Canada. Specimen is approximately 2 inches (5 centimeters) across.
A cabochon cut from apatite from the Kola Peninsula (Khibiny Region) of Russia. This gemstone is approximately 24 millimeters by 18 millimeters.
Apatite cabochon with a cat's eye from Sri Lanka. The gemstone is approximately 3 carats, and 9 millimeters by 7 millimeters.