Tiger's Eye
Quartz var. Tiger's Eye (Pseudomorph after Riebeckite) · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Trigonal crystal system; exhibits a fibrous, massive habit due to its pseudomorphic nature.
Mineral Group
Silicates (Tectosilicate subgroup)
Chemical Formula
SiO2 (with fibrous inclusions of Crocidolite/Goethite)
Formation Process
Metamorphic/Hydrothermal process termed 'pseudomorphism', where silica replaces crocidolite (blue asbestos) fibers while retaining the original fibrous structure.
About This Crystal
Opaque golden-brown specimen with a distinctive fibrous texture. Shows golden-yellow bands, a silky luster when polished, and a parallel growth of fibers.
Physical Characteristics
Color: Golden-brown to yellow; Streak: Yellow-brown; Cleavage: None (fibrous structure causes splintery fracture); Specific Gravity: 2.64-2.71; Non-fluorescent.
Optical Properties
Displays prominent chatoyancy (cat's eye effect) due to light reflecting off internal fibers. Refractive index: 1.544-1.553. Singly refractive aggregate.
Hardness & Durability
Origin Region
Primarily Griqualand West, South Africa; also found in Western Australia and Myanmar. Typically forms in iron-rich sedimentary environments.
Hardness & Durability
Mohs hardness: 6.5 to 7. Good durability and toughness, making it suitable for all types of jewelry.
Care & Maintenance
Clean with warm soapy water and a soft brush. Avoid harsh chemicals and ultrasonic cleaners which may penetrate the fibrous structure. Store separately to prevent scratching softer stones.
Rarity & Value
Common; Value is determined by the intensity of color, sharpness of the chatoyant band, and lack of dull matrix. Generally inexpensive and rarely treated, though can be dyed or heat-treated.
Special Characteristics
Exhibits chatoyancy and a 'shifting' luster; the golden color is caused by the oxidation of iron within the original crocidolite fibers into goethite.
Lore & History
Historically used by Roman soldiers for protection in battle. In traditional lore, it is considered a stone of courage, insight, and grounding, often associated with the Solar Plexus chakra.