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Gemstone profile and identification guide

Cymophane

Cymophane is the traditional mineralogical name for cat's-eye chrysoberyl.

8.5 Mohs Honey, Yellow Green Oxide (Chrysoberyl Variety: Cat's Eye)
Cymophane

Overview

Cymophane is the traditional mineralogical name for cat's-eye chrysoberyl.

Did you know? Cymophane and cat's-eye chrysoberyl refer to the same gem material in most gemological usage.

Use this profile as a collector reference and educational guide for quick on-page comparison, then validate with the interactive identification system.

Identification

Name: Cymophane

Scientific classification: Oxide (Chrysoberyl Variety: Cat's Eye)

Hardness: 8.5 Mohs

Transparency: translucent

Lustre: vitreous to silky

Crystal system: Orthorhombic

Primary colour: Honey

Secondary colour: Yellow Green

Colour family: Oranges & Yellows

Sharp eye, high RI, and chrysoberyl hardness define cymophane.

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: very hard

Hardness value: 8.5 Mohs

Chemical composition: Beryllium aluminum oxide (BeAl2O4)

Crystal system: Orthorhombic

Common locations: Sri Lanka, Brazil, India, Tanzania, Madagascar

Learn more: Gem-A gemstone education resources.

Colour Variations

Honey to yellow-green chatoyant chrysoberyl known as cymophane.

Optical effects: Chatoyancy

Detailed Gemology

Mineral species: Chrysoberyl (cymophane/cat's-eye variety)

Mineral group: Chrysoberyl group

Chemical formula: Beryllium aluminum oxide (BeAl2O4)

Mohs hardness: 8.5

Crystal system: Orthorhombic

Lustre: vitreous to silky

Transparency: translucent

Streak: White

Cleavage: Distinct in one direction

Fracture: Conchoidal to uneven

Specific gravity: 3.70-3.78

Refractive index: 1.746-1.755

Optical phenomena: Chatoyancy

Colour range: Honey, yellow-green, brownish-green

Common inclusions: Parallel tubes/needles forming eye effect

Geological environment: Pegmatites and metamorphic terrains

Principal mining regions: Sri Lanka, Brazil, India, Tanzania, Madagascar

Important commercial sources: Cymophane follows the same principal sources as cat's-eye chrysoberyl, especially Sri Lanka and Brazil

Historical significance: A classic cat's-eye gemstone category in historical and modern trade.

Common treatments: Generally untreated.

Synthetic or imitation forms: Fiber-optic glass and synthetic cat's-eye products are common imitations.

Common look-alikes: Cat's-eye quartz, cat's-eye glass, cat's-eye apatite

Jewellery uses: Used in premium cat's-eye cabochon jewellery and collector gems.

Care recommendations: High durability overall; avoid severe impact and preserve cabochon polish.

Cross-check profile data with GIA Gem Encyclopedia and Mindat entry for Cymophane.

Formation

Forms in beryllium-bearing pegmatitic and metamorphic environments with aligned inclusions creating chatoyancy.

Origin

Cymophane follows the same principal sources as cat's-eye chrysoberyl, especially Sri Lanka and Brazil

Uses

Best for: Used in premium cat's-eye cabochon jewellery and collector gems.

Ideal uses: Cabochon rings and collector stones with sharp moving eye.

Cymophane FAQ

How can I identify Cymophane?

Compare hardness (8.5 Mohs), crystal system (Orthorhombic), colour profile, and lustre (vitreous to silky) with your sample. Then cross-check related gemstones listed above.

What colour range does Cymophane appear in?

Honey to yellow-green chatoyant chrysoberyl known as cymophane.

Where is Cymophane commonly used?

Cabochon rings and collector stones with sharp moving eye.. For maintenance, follow the care guidance in this profile.