Mineral - Fluorapatite
Fluorapatite
Chemical Properties
Mineral Class
Phosphates
Toxicity
none
Formula
Ca₅(PO₄)₃F
Unit Cell
a=9.40 c=6.88 Z=2
Physical Properties
Hardness
5
Streak
white
Density
Normal (2-3,5)
Cleavage
Indistinct after {0001} and {10 1 0}
Fracture
conchoidal,
uneven
Tenacity
Brittle
Optical Properties
Color
brownredorangeyellowgreenblueturquoisepinkvioletcolorless
Birefringence
0.004
Luster
Vitreous,
Greasy
Transparency
translucent,
transparent
Pleochroism
Geomineralogical Properties
Crystal System
hexagonal
Point Group
hexagonal-dipyramidal - 6/m
Space Group
P6 3 /m (176)
Habit
blocky, granular, crusty, massive, acicular, prismatic, columnar, tabular, barrel-shaped, trapezoidal
Formation
Fluorapatite primarily forms as an accessory mineral during the cooling of igneous rocks, as well as through metasomatic processes or through chemical precipitation in calcium- and fluoride-rich environments
Paragenesis
Twinning
Rarity
Very common
Synonyms
Fluorapatite, Apatite
Composition
Elements
Mass
P₂O₅
42.01
REE₂O₃
0.28
CaO
55.52
F
3.89
O=F₂
1.63
Norway (Palache et al. 1952)
Groups and Members
Apatite-Supergroup
Apatite-Group