Fluorite
Fluorite (IMA-approved mineral name) · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Cubic (Isometric); typically forms in cubes, octahedrons, or massive habits; often displays penetration twinning
Mineral Group
Halides
Chemical Formula
CaF2 (Calcium Fluoride) often with rare earth elements like Cerium or Yttrium
Formation Process
Hydrothermal; typically forms as a vein mineral in hydrothermal deposits or in pegmatites and carbonate rocks
About This Crystal
A violet to purple semi-transparent cabochon exhibiting characteristic straight, parallel color banding and a vitreous luster
Physical Characteristics
Color: Purple, Green, Yellow, Blue; Streak: White; Cleavage: Perfect octahedral in four directions; Fracture: Subconchoidal; SG: 3.17-3.18; Strong fluorescence under UV
Optical Properties
Refractive Index: 1.434; Singly refractive (Isotropic); no pleochroism; low dispersion; can show 'Blue John' banding
Hardness & Durability
Origin Region
Prominent sources include China, Mexico, South Africa, and the United Kingdom (notably the Blue John variety)
Hardness & Durability
Mohs Hardness: 4; Brittle tenacity; easy cleavage makes it fragile for jewelry; reference mineral for 4 on Mohs scale
Care & Maintenance
Avoid ultrasonic/steam cleaners; clean with warm soapy water; keep away from acids and sunlight to prevent fading; store separately
Rarity & Value
Common mineral; value depends on color saturation and clarity; specimens with distinct banding or multiple colors are more desirable
Special Characteristics
Strong fluorescence (origin of the term), color zoning/banding, and occasionally thermoluminescence or phosphorescence
Lore & History
Historically used in carvings and vases (Blue John); traditionally associated with mental clarity and focus in crystal healing lore