Fluorite
Fluorite (IMA-approved mineral name) · Collector Mineral / Semi-Precious Gemstone / Industrial Mineral
Crystal System
Cubic (Isometric); commonly occurs in cubes, octahedrons, or as massive, granular, or banded material. Shows octahedral twinning.
Mineral Group
Halides (Simple Halides)
Chemical Formula
CaF2 (Calcium Fluoride), with trace elements like Yttrium or Cerium often contributing to specific color zones.
Formation Process
Primarily Hydrothermal; forms through precipitation from hot, mineral-rich fluids in veins or as replacement deposits in limestones. Can occur at low to moderate temperatures.
About This Crystal
This specimen is a translucent to semi-transparent fragment showing distinct purple and colorless/white color zoning. It possesses a vitreous (glassy) luster and exhibits the characteristic sharp, step-like cleavage surfaces typical of the mineral.
Physical Characteristics
Color: Purple, green, blue, yellow, or pink (this specimen is purple-banded); Streak: White; Cleavage: Perfect octahedral in four directions; Fracture: Subconchoidal to uneven; Specific Gravity: 3.18; Fluorescence: Strong blue under UV (usually longwave).
Optical Properties
Refractive Index: 1.433 (Singly refractive/Isotropic); Dispersive Power: Low (0.007); no pleochroism due to cubic symmetry.
Hardness & Durability
Origin Region
Major sources include China, Mexico, Illinois/Kentucky (USA), and England (Derbyshire). Commonly found in hydrothermal veins and sedimentary carbonate rocks.
Hardness & Durability
Mohs Hardness: 4 (Defining mineral for 4 on the scale). Fragile toughness; prone to chipping due to perfect cleavage. Not suitable for high-wear jewelry like rings.
Care & Maintenance
Clean only with warm soapy water; avoid ultrasonic and steam cleaners. Very sensitive to heat and sudden temperature changes. Purple varieties can fade if left in direct sunlight for extended periods.
Rarity & Value
Common; Value is determined by color saturation, zoning quality, and crystal perfection. Inexpensive in massive form, though rare 'Blue John' or large aesthetic crystal groups can be costly.
Special Characteristics
Displays prominent color zoning (bands of purple). Highly famous for its fluorescence; the term 'fluorescence' was actually derived from this mineral.
Lore & History
Historically used by ancient Egyptians and Romans for carved bowls and statues. In traditional lore, it is referred to as the 'Stone of Discernment,' believed to aid in mental clarity and focus. Associated with the Third Eye and Crown chakras.