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cubic Halides

Fluorite (Cube)

Formula CaF2

Crystal Structure

#! Species: Fluorite #! System: Cubic (m3m) #! Habit: Cubic with multicolour zoning cubic[m3m]:{100}[colour_zone:multi]
cubic
m3m
{100}

Quick Facts

Hardness
4.0
Specific Gravity
3.18
Refractive Index
1.434
Optical Character
Isotropic

Physical Properties

Crystal System
cubic
Hardness (Mohs)
4.0
Specific Gravity
3.18
Cleavage
Perfect octahedral {111}
Fracture
Subconchoidal to uneven
Lustre
Vitreous

Optical Properties

Refractive Index
1.434
Optical Character
Isotropic
Dispersion
0.007
Pleochroism
None
Fluorescence
Often strong (blue, green, or violet) - source of the term 'fluorescence'

Characteristics

Colours
Purple (most common)GreenBlueYellowPinkColourlessMulticoloured (zoned)
Localities
ChinaMexicoEngland (Derbyshire, Durham)USA (Illinois)SpainMorocco
Common Inclusions
Colour zoningTwo-phase fluid inclusionsSolid inclusions
Known Treatments
Irradiation (rare)Coating (rare)
Crystal Forms
cube

Diagnostic Features

Perfect octahedral cleavage {111}; strong fluorescence; isotropic; low hardness (4)

Notes

Fluorite is the mineral that gives its name to the phenomenon of fluorescence