Chemistry: |
Ca5(PO4)3(OH,F,Cl), Calcium (Fluoro, Chloro, Hydroxyl)
Phosphate |
Class: |
Phosphates |
Subclass: |
|
Group: |
Apatite |
Uses: |
as a source of phosphorous to be used in fertilizer,
rarely as a gemstone and as a mineral specimen. |
Color: |
typically green but also yellow, blue, reddish brown
and purpl e |
Luster: |
vitreous to greasy and gumdrop. |
Transparency: |
Crystals are transparent to translucent. |
Crystal System: |
hexagonal; 6/m |
Crystal Habits: |
include the typical hexagonal prism with the hexagonal
pyramid or a pinacoid or both as a termination. Also
accicular, granular, reniform and massive. A cryptocrystalline
variety is called collophane and can make up a rock
type called phosphorite and also can replace fossil
fragments. |
Cleavage: |
indistinct in one basal direction. |
Fracture: |
conchoidal. |
Hardness: |
5 |
Specific Gravity: |
approximately 3.1 - 3.2 (average for translucent minerals) |
Streak |
white. |
Other Characteristics: |
An unusual "partially dissolved" look similar
to the look of previously sucked on hard candy. |
Associated Minerals: |
hornblende, micas, nepheline and calcite . |
Local Occurance: |
Bear Lake Occurrence, Davis Hill, Davis Quarry, Desmont,
Dwyer, Eagle's Nest, Goulding-Keene Quarry, Quirk Lake,
Rankin Mine, Warwickite Occurrence |
Best Field Indicators: |
crystal habit, color, hardness and look |
Description:
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. |
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