THE MINERAL APATITE

Apatite is actually three different minerals depending on the predominance
of either fluorine, chlorine or the hydroxyl group.

These ions can freely substitute in the crystal lattice and all three are usually present
in every specimen although some specimens have been close to 100% in one or the other.

The rather non-inventive names of these minerals are Fluorapatite, Chlorapatite and
Hydroxylapatite.

The three are usually considered together due to the difficulty in distinguishing them
in hand samples using ordinary methods.

An irony of the name apatite is that apatite is the mineral that makes up the teeth in
all vertebrate animals as well as their bones. Get it? Apatite - teeth!

Anyway, the name apatite comes from a Greek word meaning to decieve in allusion
to its similarity to other more valuable minerals such as olivine, peridot and beryl .

Apatite is widely distributed in all rock types; igneous, sedimentary and
metamorphic, but is usually just small disseminated grains or cryptocrystalline
fragments.

Large well formed crystals though can be found in certain contact metamorphic
rocks.

Very gemmy crystals of apatite can be cut as gems but the softness of apatite
prevents wide distribution or acceptance of apatite as a gemstone.