metamorphic
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Hardness: 6.5-7 (Mohs scale); Color: Golden yellow to brown with chatoyant bands; Luster: Silky; Crystal structure: Trigonal (fibrous texture); Cleavage: None; Specific Gravity: 2.64-2.71.
- Hardness
- 6
- Color
- Golden yellow to brown with chatoyant bands
- Luster
- Silky
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.5-7 (Mohs scale); Color: Golden yellow to brown with chatoyant bands; Luster: Silky; Crystal structure: Trigonal (fibrous texture); Cleavage: None; Specific Gravity: 2.64-2.71.
Formation & geological history
Formed through the pseudomorphism of crocidolite asbestos fibers by chalcedony quartz. Heat and pressure during tectonic movements replace the blue asbestos with quartz and iron oxides while maintaining the fibrous structure. Primarily found in Precambrian rocks.
Uses & applications
Predominantly used as a gemstone for jewelry (cabochons, beads), decorative carvings, and as a popular specimen for rock collectors.
Geological facts
The optical effect seen in Tiger's Eye is called chatoyancy, or the 'cat's-eye effect.' It was historically worn as an amulet against curses and bad luck. The largest deposits are in the Griquatown area of South Africa.
Field identification & locations
Identified in the field by its distinct parallel bands of golden-brown color and the way light reflects off the fibrous surface as the stone is turned (chatoyancy). Common locations include South Africa, Australia, Burma, and India.
More like this
