Fluorite
Fluorite (Fluorospar) · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Cubic (Isometric); typically occurs as cubic or octahedral crystals, or in massive, granular, or banded habits
Mineral Group
Halides
Chemical Formula
CaF2 (Calcium Fluoride) with possible trace elements of Rare Earth Elements (REE) for color
Formation Process
Primarily Hydrothermal; forms in veins as a gangue mineral associated with metallic ores, or in sedimentary carbonaceous rocks and pegmatites
About This Crystal
A translucent to transparent specimen showing distinct color zoning. This piece displays a brownish-yellow to golden core with a contrasting pale green band on one end. It has a vitreous (glassy) luster and visible internal cleavage planes.
Physical Characteristics
Color: Yellow and Green; Streak: White; Cleavage: Perfect octahedral (four directions); Fracture: Subconchoidal to uneven; Specific Gravity: 3.175–3.184; Fluorescence: Strong blue-violet under UV light
Optical Properties
Refractive Index: 1.434 (Isotropic); Birefringence: None; Dispersion: 0.007; Diaphaneity: Transparent to translucent
Hardness & Durability
Origin Region
Prominent sources include China, Mexico, South Africa, and the United Kingdom (notably the Blue John mine in Derbyshire)
Hardness & Durability
Mohs Hardness: 4; Toughness: Poor due to perfect cleavage; brittle and easily scratched compared to glass or quartz
Care & Maintenance
Clean with warm soapy water only; avoid ultrasonic and steam cleaners. Store separately from harder stones to prevent scratches. Highly sensitive to heat and acidic chemicals; avoid prolonged sunlight exposure as colors can fade.
Rarity & Value
Common mineral; value is determined by color zoning intensity, transparency, and crystal formation. Large, well-formed cubic specimens are highly prized by collectors.
Special Characteristics
Displays prominent color zoning (banding). Notable for its strong fluorescence (the phenomenon was actually named after this mineral).
Lore & History
Historically used by ancient Egyptians and Romans for carved vessels and jewelry. In metaphysical lore, it is often called the 'Genius Stone,' associated with mental clarity, focus, and the heart and solar plexus chakras depending on color.