Tiger's Eye
Last updated: April 2026
Chatoyant quartz formed by pseudomorphous replacement of crocidolite asbestos fibers with silica. Golden-yellow Tiger's Eye results from iron oxide staining of the silica pseudomorph. Hawk's Eye is the blue-grey unaltered variety. Red Tiger's Eye (ox-blood) is heat-treated. Always cut en cabochon to display chatoyancy.
Physical & Optical Properties
RI Range1.544–1.553
SG Range2.64–2.71
SG Typical2.65
Hardness (Mohs)7
Crystal SystemTrigonal
Optic CharacterAggregate
Dispersion0.013
Fluorescence LWInert
Fluorescence SWInert
Chelsea FilterInert
PleochroismNone
ColorsYellow Orange, Brown
SpeciesQuartz
Related: Quartz Varieties
Key Differentiators
- Chatoyancy (cat's eye effect) from parallel fibrous structure
- Golden yellow to red-brown silky luster
- Fibrous pseudo-morphous structure after crocidolite asbestos
- Inert under UV; quartz RI and SG
Treatments
- Heat Treatment (red Tiger's Eye / Ox Blood — from golden via heat)
- Dyed (blue, green, and other non-natural colors)
Price Context
Natural — low ($/ct)$1
Natural — high ($/ct)$20
NotePer carat; common commercial gem; South African origin dominant; value driven by quality of chatoyancy and color intensity
Price context is approximate. GemID is not an appraisal tool. Results are indicators, not certified valuations.
Measurement Guides
Identifying a tiger's eye? GemID walks through these tests in order — RI, SG, fluorescence, and more.
Try GemID Free →