mineral
Fluorite
Calcium Fluoride (CaF2)
Hardness: 4 on Mohs scale; Color: Green, purple, blue, or yellow; Luster: Vitreous; Crystal system: Isometric/Cubic; Cleavage: Perfect octahedral; Specific gravity: 3.18.
- Hardness
- 4 on Mohs scale
- Color
- Green, purple, blue, or yellow
- Luster
- Vitreous
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Physical properties
Hardness: 4 on Mohs scale; Color: Green, purple, blue, or yellow; Luster: Vitreous; Crystal system: Isometric/Cubic; Cleavage: Perfect octahedral; Specific gravity: 3.18.
Formation & geological history
Forms primarily in hydrothermal veins, often as a gangue mineral associated with metallic ores. It can also occur in sedimentary rocks like limestone and some igneous rocks.
Uses & applications
Used as a flux in steel making, in the manufacture of hydrofluoric acid, in high-performance telescopes/camera lenses, and as a popular ornamental stone and collector specimen.
Geological facts
Fluorite is famous for its wide range of colors and was the first mineral in which the phenomenon of fluorescence was studied and named. It glows under ultraviolet light.
Field identification & locations
Identify by its 4-way octahedral cleavage, its relatively low hardness (can be scratched by a pocket knife), and its cubic crystal habit. Common in Illinois (USA), China, and Mexico.
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Other mineral specimens
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Schist
Schist
Metamorphic
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Gypsum (variety Selenite or Alabaster)
Calcium sulfate dihydrate (CaSO4·2H2O)
Mineral
Nephrite Jade
Nephrite
Mineral/Rock
Granite
Granite (Phaneritic intrusive igneous rock)
igneous