Rock Identifier
Tiger's Eye (Pseudomorph of Quartz after Crocidolite (SiO2)) — mineral
mineral

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

Hardness: 6.5-7 on Mohs scale; Color: Golden-yellow to brown; Luster: Silky; Crystal structure: Trigonal (fibrous); Cleavage: None; Specific Gravity: 2.64-2.71. Known for its strong chatoyancy (cat's eye effect).

Hardness
6
Color
Golden-yellow to brown
Luster
Silky
Identified More mineral

Identify your own rocks.

Get a report just like this from any photo, free.

Physical properties

Hardness: 6.5-7 on Mohs scale; Color: Golden-yellow to brown; Luster: Silky; Crystal structure: Trigonal (fibrous); Cleavage: None; Specific Gravity: 2.64-2.71. Known for its strong chatoyancy (cat's eye effect).

Formation & geological history

Formed primarily through pseudomorphism, where quartz replaces fibrous crocidolite (asbestos) while maintaining its fibrous structure. It typically occurs in metamorphic rocks and is often found in banded iron formations.

Uses & applications

Primarily used in jewelry for cabochons, beads, and carvings. Also popular as a decorative stone in small ornamental objects and highly valued by mineral collectors for its unique optical properties.

Geological facts

The chatoyant effect is caused by the reflection of light off the parallel fibers of the mineral. It is often associated with protection and grounding in metaphysical traditions, and historically it was used by Roman soldiers to ward off evil.

Field identification & locations

Identified in the field by its distinct golden-brown bands and the shifting light effect (cat's eye) when rotated. Major deposits are found in South Africa, Australia, Burma, India, and Namibia.