metamorphic
Tiger's Eye
Pseudomorph of quartz after crocidolite (SiO2 with iron inclusions)
Hardness: 6.5-7 (Mohs); Color: Golden to red-brown with silky luster; Crystal Structure: Trigonal/Hexagonal; Cleavage: None; Specific Gravity: 2.64-2.71. Known for its distinct chatoyancy.
- Hardness
- 6
- Color
- Golden to red-brown with silky luster
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.5-7 (Mohs); Color: Golden to red-brown with silky luster; Crystal Structure: Trigonal/Hexagonal; Cleavage: None; Specific Gravity: 2.64-2.71. Known for its distinct chatoyancy.
Formation & geological history
Formed through the replacement of fibrous asbestos minerals (crocidolite) by silica (quartz) while preserving the fibrous structure. Primarily formed in Precambrian metamorphic rocks roughly 2 billion years old.
Uses & applications
Extensively used in jewelry (cabochons, beads), decorative carvings, and as a popular semi-precious gemstone for collectors and metaphysical enthusiasts.
Geological facts
Tiger's Eye is a classic example of a 'pseudomorph' (false form). It changes its appearance as the observer moves, an optical effect called chatoyancy caused by light reflecting off the internal fibers.
Field identification & locations
Identify in the field by its distinct golden-yellow to brown bands and the 'moving' light effect when rotated. Mostly found in South Africa, Western Australia, USA, and India.
More like this
