Tigers Eye
Quartz var. Tigers Eye (Pseudomorph of Quartz after Crocidolite) · Semi-Precious Gemstone
Crystal System
Trigonal (specifically Hexagonal as a variety of Quartz); fibers are usually Orthorhombic or Monoclinic in origin. Typically found in massive, fibrous habits.
Mineral Group
Silicates (Tectosilicates)
Chemical Formula
SiO2 with inclusions of iron oxides (primarily Limonite or Goethite)
Formation Process
Metamorphic/Hydrothermal. It forms as a pseudomorph when quartz replaces the fibrous mineral crocidolite (blue asbestos) while retaining its fibrous structure, followed by the oxidation of iron.
About This Crystal
An opaque to translucent gemstone with a rich golden to reddish-brown color. It displays a silky luster and distinct chatoyancy (cat-eye effect) caused by the parallel orientation of the oxidized mineral fibers.
Physical Characteristics
Color: Golden yellow to brown; Streak: Yellow-brown; Cleavage: None; Fracture: Splintery or conchoidal; Specific Gravity: 2.64–2.71; Fluorescence: Generally inert.
Optical Properties
Refractive Index: 1.544–1.553; Birefringence: 0.009; Optical Phenomenon: Chatoyancy (silky shimmer); Pleochroism: None; Luster: Silky (fibrous) to vitreous.
Hardness & Durability
Origin Region
South Africa (Griatland West), Australia, India, Burma, Namibia, and the United States (California).
Hardness & Durability
Mohs Hardness: 6.5–7; Toughness: Good (durable for most jewelry use); Stability: Stable against light and most common chemicals.
Care & Maintenance
Wash with warm soapy water and a soft brush. Avoid harsh chemicals like hydrofluoric acid. Strong heat may alter the color (turning it red/Oxeye). Storage: Keep away from harder stones like Sapphire to prevent scratches.
Rarity & Value
Common. Value is determined by the quality of chatoyancy, color saturation, and lack of dull matrix. Generally inexpensive and frequently available in tumbled or cabochon forms.
Special Characteristics
Displays chatoyancy, where a band of light moves across the surface. When the fibers remain unoxidized and blue, it is known as Hawks Eye.
Lore & History
Historically worn by Roman soldiers for protection in battle and used as an 'all-seeing eye' in ancient amulets. In modern lore, it is believed to enhance willpower, provide mental clarity, and ground the user’s energy (associated with the Solar Plexus chakra).