metamorphic
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Hardness: 6.5-7.0 (Mohs); Color: Golden to red-brown; Luster: Silky; Crystal structure: Trigonal (fibrous); Cleavage: None; Specific Gravity: 2.64-2.71; Chatoyancy (cat's-eye effect).
- Hardness
- 6
- Color
- Golden to red-brown
- Luster
- Silky
Identified More metamorphic →
Explore Tiger's Eye in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.5-7.0 (Mohs); Color: Golden to red-brown; Luster: Silky; Crystal structure: Trigonal (fibrous); Cleavage: None; Specific Gravity: 2.64-2.71; Chatoyancy (cat's-eye effect).
Formation & geological history
Formed when quartz replaces the mineral crocidolite (blue asbestos) through a process of pseudomorphism, typically in iron formations within metamorphic rock environments. Most specimens are over 2 billion years old.
Uses & applications
Primarily used in jewelry (cabochons, beads), decorative carvings, and as a popular collectible stone in metaphysical practices.
Geological facts
The characteristic silky luster comes from the parallel growth of quartz crystals and altered amphibole fibers. A blue variety exists called Hawk's Eye, and a heat-treated red variety is known as Bull's Eye.
Field identification & locations
Identify by looking for moving bands of light (chatoyancy) when the stone is rotated under a light source. Commonly found in South Africa, Western Australia, India, and Burma.
More like this
