Chlorapatite

Chlorapatite is the chlorine end-member of the Apatite Group.
General Information
A variety or type of:Apatite
Other Names/Trade Names:
Chemical Formula
Ca
 
5
(PO
 
4
)
 
3
Cl
Anthony et al, Handbook of mineralogy (2001)
Photos of natural/un-cut material from mindat.org
Physical Properties of Chlorapatite
Mohs Hardness5
Anthony et al, Handbook of mineralogy (2001)
Specific Gravity3.17 to 3.18
Anthony et al, Handbook of mineralogy (2001)
TenacityBrittle
Anthony et al, Handbook of mineralogy (2001)
Cleavage QualityPoor
Anthony et al, Handbook of mineralogy (2001)
Optical Properties of Chlorapatite
Refractive Index1.665 to 1.667
Anthony et al, Handbook of mineralogy (2001)
Optical CharacterUniaxial/-
Anthony et al, Handbook of mineralogy (2001) may be biaxial
PleochroismWeak to moderate; in pale colors.
Anthony et al, Handbook of mineralogy (2001)
Colour
Colour (General)Greenish yellow, pinkish white, light greenish gray
Anthony et al, Handbook of mineralogy (2001)
TransparencyTransparent,Translucent
Anthony et al, Handbook of mineralogy (2001)
LustreVitreous
Anthony et al, Handbook of mineralogy (2001)
Crystallography of Chlorapatite
Crystal SystemHexagonal,Monoclinic
Anthony et al, Handbook of mineralogy (2001) Hexagonal or monoclinic.
HabitAs prismatic hexagonal crystals, to 5 cm; granular, massive, may be in zoned intergrowths with fluorapatite.
Anthony et al, Handbook of mineralogy (2001)
Geological Environment
Where found:Relatively much rarer than fluorapatite or hydroxylapatite, formed in F-deficient environments. In calcsilicate marble; an accessory mineral in layered mafic intrusions; in veins through diabase; replacing triphylite in granite pegmatite. In meteorites.
Anthony et al, Handbook of mineralogy (2001)
Further Information
Mineral information:Chlorapatite information at mindat.org
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