CHRYSOBERYL CAT’S-EYE
Chrysoberyl Cat’s-eye
Chrysoberyl
Chrysoberyl displaying a single luminous band. The term cat's-eye also describes an optical effect seen in other materials.
GEM PROFILE
Basic properties
- Mineral or material
- Chrysoberyl
- Main chemical composition
- BeAl₂O₄
- Crystal & structure
- Orthorhombic
Parallel microscopic inclusions reflect light into a moving band resembling a cat's eye.
- Typical colors
- Yellow, honey, yellowish green and brown
- Mohs hardness
- 8.5
A measure of scratch resistance, distinct from resistance to impact or breakage.
About hardness and durability - Representative sources
Examples of known sources. Determining the origin of an individual stone requires examination and comparison with reference material.
- Common cutting styles
- A domed cabochon, oriented to show a distinct band of light.
Explore cutting styles
LOOK A LITTLE CLOSER
What to observe
Move a small point light source to see the band move. Quartz and other gems can show the same effect, so confirm both mineral identity and phenomenon.
TREATMENT & CARE
Treatments & care
Treatments & identification
Glass imitations can also display a similar band. Gemological tests are used to establish the material's identity.
Everyday care
Remove dirt with a soft cloth and avoid strong impacts. If treatment or fracture information is unknown, ask a specialist about suitable care.
Cleaning depends on treatment, inclusions and mounting. If a stone's condition is unknown, ask your jeweler or a gem specialist before cleaning.
READING & REFERENCES
References
Public sources for learning about this gemstone's general properties.
- Handbook of Mineralogy · Mineral data (PDF)
- GIA · Gemological reference
- CGL · Gemological reference (Japanese)
This dictionary provides general educational information. Values are representative and do not identify or grade an individual stone. Locality examples include historical deposits.
Sources checked: October 19, 2026