Name:

Apatite

Chem:

Ca5(F,Cl,OH)(PO4)3
Calcium Fluoro-Phosphate

Crystal:

hexagonal (prism very common)

Color:

colorless, blue, green, yellow, violet

Refrac.Index:

1.63 - 1.646

Birefraction:

0.003

Hardness:

5

Spec. Grav.:

3.17 - 3.23

Fracture:

conchoidal

Cleavage:

poor

Environment:

stable in many environments, hydrothermal veins, metamorphics, and even via chemical deposition

Association:

pegmatites, al manner of metamorphics

Locals:

| Brazil | Sri Lankra | Canada | Maine, USA |

Misc:

from the Greek word "apatos" meaning "deception", because of its wide variety of colors and crystals shapes. soluble in HCl, often fluorescent or thermoluminescent. Used mainly as a source of phosphates for fertilizer.

Gem info:

The green variety is sometimes called "asparagus stone", it is not common in the jewelry trade because it is both soft and very brittle. Mainly purchased by gem collectors.

pairblue stones