metamorphic
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Hardness: 6.5-7 Mohs; Color: Golden yellow to brown with chatoyant stripes; Luster: Silky; Crystal Structure: Trigonal (fibrous aggregate); Cleavage: None; Specific Gravity: 2.64-2.71
- Hardness
- 6
- Color
- Golden yellow to brown with chatoyant stripes
- 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 brown with chatoyant stripes; Luster: Silky; Crystal Structure: Trigonal (fibrous aggregate); Cleavage: None; Specific Gravity: 2.64-2.71
Formation & geological history
Formed through the pseudomorphism of crocidolite (blue asbestos) by quartz. As quartz replaces the crocidolite, it maintains the fibrous structure. Iron oxides (limonite) provide the yellow-gold color. Generally found in Precambrian banded iron formations.
Uses & applications
Primarily used in jewelry (cabochons, beads), decorative carvings, lapidary arts, and as a popular metaphysical/collecting gemstone.
Geological facts
It is a 'pseudomorph,' meaning 'false form,' because the quartz minerals have taken over the shape of a different mineral. It exhibits a unique optical effect called chatoyancy, which creates moving bands of light similar to a cat's eye.
Field identification & locations
Identify by its golden-brown parallel fibers and the 'cat's eye' shimmer when tilted under light. Commonly found in South Africa, Western Australia, USA, and India. Collectors look for high luster and distinct color banding.
More like this
