Fluorite
Fluorite · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Cubic (Isometric); in the image, the specimen is carved into a hex-tower habit with a prismatic body and pyramidal termination.
Mineral Group
Halides
Chemical Formula
CaF2 (Calcium Fluoride) with internal impurities of Rare Earth Elements (REE) or hydrocarbons
Formation Process
Hydrothermal; usually forms as a vein mineral in carbonate rocks or near igneous intrusions under low to moderate temperatures.
About This Crystal
A translucent to transparent specimen showing color zoning with bands of teal, green, and deep purple. It possesses a vitreous (glassy) luster and visible internal cleavage planes.
Physical Characteristics
Color: Multi-colored (teal, green, purple); Streak: White; Cleavage: Perfect octahedral in four directions; Fracture: Subconchoidal to uneven; Specific Gravity: 3.175–3.184; Fluorescence: Strong blue-violet under UV light.
Optical Properties
Refractive Index: 1.433–1.435; Birefringence: None (singly refractive/isotropic); Dispersion: Low (0.007); no pleochroism.
Hardness & Durability
Origin Region
Major sources include China, Mexico, England (Blue John), and Brazil; often occurs in hydrothermal veins.
Hardness & Durability
Mohs Hardness: 4; Toughness: Poor due to easy cleavage; Fragile and easily scratched by glass or steel; not recommended for high-impact jewelry.
Care & Maintenance
Wash with lukewarm soapy water; avoid ultrasonic or steam cleaners; sensitive to thermal shock and strong acids; should be stored away from harder gemstones and direct sunlight.
Rarity & Value
Common; Value is determined by color intensity, banding patterns, and size; Polished points are generally affordable, ranging from $10-$40 depending on size.
Special Characteristics
Strong fluorescence (for which the mineral is the namesake); distinct color zoning/banding; 'Rainbow' Fluorite variety with multiple spectral colors.
Lore & History
Historically used by ancient Egyptians and Romans for carved vessels and bowls; traditionally associated with mental clarity, focus, and the heart or throat chakras.