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

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

Mohs hardness of 7, silky luster, yellow-golden to red-brown color with fibrous chatoyancy, trigonal crystal system, no cleavage, specific gravity around 2.64-2.71.

Identified More metamorphic
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Physical properties

Mohs hardness of 7, silky luster, yellow-golden to red-brown color with fibrous chatoyancy, trigonal crystal system, no cleavage, specific gravity around 2.64-2.71.

Formation & geological history

Formed through a metamorphic process known as pseudomorphism, where quartz replaces the asbestos mineral crocidolite over time while preserving the original fibrous structure.

Uses & applications

Popular gemstone used in lapidary work, jewelry (cabochons, beads, rings), carvings, and as decorative collector specimens.

Geological facts

The shimmering effect in Tiger's Eye is called chatoyancy (cat's-eye effect), which occurs when light reflects off the fibrous parallel inclusions of quartz and iron oxides.

Field identification & locations

Identified by its golden-yellow to brown silky banding and distinct chatoyant luster. Major source deposits are in South Africa (Northern Cape), Australia, India, Namibia, and Brazil.