metamorphic
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Hardness: 6.5-7 Mohs; Color: Golden yellow to deep brown with silky banding; Luster: Silky; Crystal system: Trigonal (fibrous); Cleavage: None; Specific Gravity: 2.64-2.71; Notable for chatoyancy (cat-eye effect).
- Hardness
- 6
- Color
- Golden yellow to deep brown with silky banding
- 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; Color: Golden yellow to deep brown with silky banding; Luster: Silky; Crystal system: Trigonal (fibrous); Cleavage: None; Specific Gravity: 2.64-2.71; Notable for chatoyancy (cat-eye effect).
Formation & geological history
Formed through the pseudomorphism of crocidolite (asbestos) fibers by quartz. The iron in the original mineral oxidizes to create the yellow/brown hues. Chiefly found in Precambrian iron formations (approx. 2 billion years old) such as the Northern Cape Province of South Africa.
Uses & applications
Predominantly used as a gemstone for jewelry (cabochons, beads), decorative carvings, and metaphysical collecting. Historically used as a protective amulet.
Geological facts
It is a 'pseudomorph,' meaning one mineral replaces another while retaining the original mineral's shape. Roman soldiers wore it for protection in battle. Variations include 'Hawk\'s Eye' (blue) and 'Bull\'s Eye' (red, due to heat).
Field identification & locations
Identify by its distinctive silky luster and moving bands of light (chatoyancy) when tilted. Most abundant in South Africa and Western Australia. Collectors look for sharp, distinct banding and high surface polish.
More like this
