Gemstone profile and identification guide
Cat's Eye Quartz
Cat's-eye quartz is quartz showing a chatoyant eye caused by aligned fibrous or needle inclusions.
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Overview
Cat's-eye quartz is quartz showing a chatoyant eye caused by aligned fibrous or needle inclusions.
Did you know? The cat's-eye in quartz is usually softer and broader than in chrysoberyl.
Use this profile as a collector reference and educational guide for quick on-page comparison, then validate with the interactive identification system.
Identification
Name: Cat's Eye Quartz
Scientific classification: Silicate (Quartz Variety with Chatoyancy)
Hardness: 7 Mohs
Transparency: translucent
Lustre: vitreous to silky
Crystal system: Trigonal
Primary colour: Grey
Secondary colour: Honey
Colour family: Greys
Quartz properties with moderate eye sharpness distinguish it from cat's-eye chrysoberyl.
Verification Status
Status: verified-core-fields
Reference priority: GIA, Gem-A, Mindat, International Gem Society
Core identity, locality, and physical-property fields reviewed against standard gemological references.
Values are reported as practical gemological ranges where appropriate.
Physical Properties
Hardness category: hard
Hardness value: 7 Mohs
Chemical composition: Silicon dioxide (SiO2)
Crystal system: Trigonal
Common locations: India, Sri Lanka, Brazil, Madagascar, South Africa
Learn more: Gem-A gemstone education resources.
Colour Variations
Quartz cabochons with a chatoyant eye, usually in grey to honey tones.
Optical effects: Chatoyancy
Detailed Gemology
Mineral species: Quartz (chatoyant variety)
Mineral group: Quartz group
Chemical formula: Silicon dioxide (SiO2)
Mohs hardness: 7
Crystal system: Trigonal
Lustre: vitreous to silky
Transparency: translucent
Streak: White
Cleavage: None
Fracture: Conchoidal
Specific gravity: 2.65
Refractive index: 1.544-1.553
Optical phenomena: Chatoyancy
Colour range: Grey, greenish-grey, honey, brown
Common inclusions: Parallel fibers, rutile needles, hollow tubes
Geological environment: Hydrothermal and metamorphic quartz-bearing environments
Principal mining regions: India, Sri Lanka, Brazil, Madagascar, South Africa
Important commercial sources: Commercial cat's-eye quartz is widely sourced, commonly from India and Sri Lanka
Historical significance: Long-used cat's-eye alternative at lower cost than chrysoberyl.
Common treatments: Dyeing and impregnation may occur in lower-grade material.
Synthetic or imitation forms: Fiber-optic glass cat's-eye imitations are common.
Common look-alikes: Cat's-eye chrysoberyl, cat's-eye apatite, glass cat's-eye
Jewellery uses: Used in cabochon rings, pendants, and collector effect stones.
Care recommendations: Durable for jewellery; protect polished dome from abrasion to maintain sharp eye.
Cross-check profile data with GIA Gem Encyclopedia and Mindat entry for Cat's Eye Quartz.
Formation
Forms when fibrous inclusions are oriented in quartz and cut en cabochon to reveal chatoyancy.
Origin
Commercial cat's-eye quartz is widely sourced, commonly from India and Sri Lanka
Uses
Best for: Used in cabochon rings, pendants, and collector effect stones.
Ideal uses: Cabochons with centered eye under directional light.
Care
Durable for jewellery; protect polished dome from abrasion to maintain sharp eye.
Need another candidate? Use advanced gemstone search or return to the identification guide.
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Commonly confused gemstones
Cat's Eye Quartz FAQ
How can I identify Cat's Eye Quartz?
Compare hardness (7 Mohs), crystal system (Trigonal), colour profile, and lustre (vitreous to silky) with your sample. Then cross-check related gemstones listed above.
What colour range does Cat's Eye Quartz appear in?
Quartz cabochons with a chatoyant eye, usually in grey to honey tones.
Where is Cat's Eye Quartz commonly used?
Cabochons with centered eye under directional light.. For maintenance, follow the care guidance in this profile.
Scientific References
GIA: general gemstone identity (reviewed) - Batch 03 factual verification pass.
Gem-A: gemological terminology and testing references (reviewed) - Batch 03 factual verification pass.
Mindat: mineral species and principal localities (reviewed) - Batch 03 factual verification pass.
International Gem Society: gem trade context and treatment overview (reviewed) - Batch 03 factual verification pass.