Gemstone profile and identification guide
Alexandrite is the colour-change variety of chrysoberyl, typically shifting from green to bluish green in daylight to red to purplish red under incandescent light. Commercial alexandrite is sourced mainly from Brazil, Sri Lanka, and East Africa, with the Russian Urals important historically.
Alexandrite is the colour-change variety of chrysoberyl, typically shifting from green to bluish green in daylight to red to purplish red under incandescent light. Commercial alexandrite is sourced mainly from Brazil, Sri Lanka, and East Africa, with the Russian Urals important historically.
Did you know? Alexandrite became famous in nineteenth-century Russia, where the red-and-green shift echoed the imperial colours associated with the tsars.
Use this profile as a collector reference and educational guide for quick on-page comparison, then validate with the interactive identification system.
Name: Alexandrite
Scientific classification: Oxide (Chrysoberyl)
Hardness: 8.5 Mohs
Transparency: transparent
Lustre: vitreous
Crystal system: Orthorhombic
Primary colour: Green
Secondary colour: Brown
Colour family: Greens
The decisive test is the colour shift under different light sources. Compare it with green chrysoberyl, tourmaline, or garnet lookalikes and pay close attention to whether the change is broad and obvious rather than a slight brownish cast.
Status: verified-core-fields
Reference priority: GIA, Gem-A, Mindat, International Gem Society
Core identity fields reviewed against consensus gemological references (GIA/Gem-A/Mindat/IGS).
Some market- and locality-level details may still require citation-grade source notes for publication workflows.
Hardness category: medium
Hardness value: 8.5 Mohs
Chemical composition: Beryllium aluminum oxide (BeAl2O4)
Crystal system: Orthorhombic
Common locations: Brazil (Minas Gerais), Sri Lanka, Tanzania, India, Russia (historic Ural localities)
Learn more: Gem-A gemstone education resources.
Alexandrite sits in the greens grouping here, usually reading first as green with brown appearing as a secondary note or modifier. Some specimens also show colour change, which can alter the way the colour is perceived under changing light.
Optical effects: Colour Change, Chatoyancy (rare)
Mineral species: Chrysoberyl
Mineral group: Chrysoberyl group
Chemical formula: Beryllium aluminum oxide (BeAl2O4)
Mohs hardness: 8.5
Crystal system: Orthorhombic
Lustre: vitreous
Transparency: transparent
Streak: White
Cleavage: Distinct in one direction
Fracture: Conchoidal to uneven
Specific gravity: 3.70-3.78
Refractive index: 1.741-1.760
Optical phenomena: Colour Change, Chatoyancy (rare)
Colour range: Green, Brown, Purple, Red, Colour Change
Common inclusions: Needle-like rutile, fingerprint inclusions, fluid inclusions
Geological environment: Pegmatites and metamorphic rocks with chromium-bearing conditions
Principal mining regions: Brazil (Minas Gerais), Sri Lanka, Tanzania, India, Russia (historic Ural localities)
Important commercial sources: Brazil, Sri Lanka, Tanzania, India; classic historic material from the Ural Mountains in Russia
Historical significance: Named in 19th-century Russia and historically associated with imperial Russian jewellery.
Common treatments: Generally untreated; some material may be clarity enhanced.
Synthetic or imitation forms: Flux-grown synthetic alexandrite, colour-change sapphire simulants
Common look-alikes: Colour-change sapphire, garnet-and-glass composites
Jewellery uses: Lapidaries usually cut it to emphasise movement of light, so ornamental objects and statement jewellery are common uses.
Care recommendations: Durable for jewellery; avoid sharp impact along cleavage and avoid harsh thermal shock.
Cross-check profile data with GIA Gem Encyclopedia and Mindat entry for Alexandrite.
Forms in beryllium-rich pegmatitic and metamorphic environments where chromium is available as a chromophore. Gem-quality crystals are recovered from pegmatites and secondary placer concentrations.
Brazil, Sri Lanka, Tanzania, India; classic historic material from the Ural Mountains in Russia
Best for: Lapidaries usually cut it to emphasise movement of light, so ornamental objects and statement jewellery are common uses.
Ideal uses: Best for jewellery and display pieces where colour, pattern, or internal effect matters more than maximum wear resistance.
With Mohs hardness about 8.5, alexandrite is suitable for most jewellery. Avoid harsh impact and steam cleaning of heavily included stones; use warm water, mild soap, and a soft brush.
Need another candidate? Use advanced gemstone search or return to the identification guide.
Compare hardness (8.5 Mohs), crystal system (Orthorhombic), colour profile, and lustre (vitreous) with your sample. Then cross-check related gemstones listed above.
Alexandrite sits in the greens grouping here, usually reading first as green with brown appearing as a secondary note or modifier. Some specimens also show colour change, which can alter the way the colour is perceived under changing light.
Best for jewellery and display pieces where colour, pattern, or internal effect matters more than maximum wear resistance.. For maintenance, follow the care guidance in this profile.
GIA: general gemstone identity (reviewed) - Reviewed as a direct core gemstone profile.
Gem-A: gemological education and terminology (reviewed) - Reviewed as a direct core gemstone profile.
Mindat: mineral species and locality index (reviewed) - Reviewed as a direct core gemstone profile.
International Gem Society: collector-facing gem reference (reviewed) - Reviewed as a direct core gemstone profile.
