| CHEMICAL COMPOSITION & NAME | Ca(F,CL)Ca4(PO4)3 - A complex Calcium Phosphate |
| CRYSTALLOGRAPHY | Hexagonal |
| REFRACTIVE INDEX | 1.632 - 1.64 |
| HARDNESS | 5 |
| SPECIFIC GRAVITY | 3.10 - 3.35 |
| CLEAVAGE | Poor |
| HEAT SENSITIVE | Yes, very. |
| BI-REFRINGENCE | 0.002 - 1.004 |
| WEARABILITY | Very Good |
| OPTIC SIGN | Negative |
| OPTICAL CHARACTER | Uniaxial |
| SPECIAL CARE INSTRUCTIONS | Avoid rough handling |
| ENHANCEMENTS | None |
Apatite, a naturally occurring gemstone is a stone seldom found in jewelry stores and virtually unknown to the general public. It is beloved by collectors for its many different colors and forms. Only with the recent availability of the neon blue-green variety from Madagascar, has its jewelry use increased. The color of the best specimens of this type rivals the famed Paraiba tourmalines, but alas, this gem lacks their toughness and hardness. At 5 on the Mohs scale, apatite must be cut, set, and worn gently. Earrings, pendants, pins, and tie tacks are probably safe, but ring use should be limited to occasional wear pieces with protective settings. Care for this stone is similar to that given opals, it is heat and shock sensitive, so steamers and ultrasonics must be avoided. Gems are available in white,yellows, pink, violet and various shades of blues and greens. Some of the blues and yellows show chatoyancy and can be cut as cat's eyes.
Main sources are Brazil, Canada, India, Mozambique, and Madagascar. The name "apatite" has been taken from a Greek word "apate" which means to deceive. It is so named because one can easily get apatite confused with a variety of other stones like tourmaline, peridot and beryl. Other sources of apatite are Mexico, Sri Lanka, Norway and The United States. Apatite clears confusion in the mental strata.