RocksdayAlexandrite vs Chrysoberyl
To tell Alexandrite from Chrysoberyl: Ordinary chrysoberyl stays yellow-green in every light.
The color-change variety of chrysoberyl: green in daylight and red or purple under an incandescent bulb.
Photo: Parent Géry, Public domain
A very hard beryllium aluminum oxide. Its varieties include color-changing alexandrite and cat's eye.
Photo: Matteo Chinellato, CC BY-SA 3.0
Key differences
- Ordinary chrysoberyl stays yellow-green in every light.
- Alexandrite is the color-change variety: green in daylight, redder under a warm bulb.
Side by side
| Property | Alexandrite | Chrysoberyl |
|---|---|---|
| Type | Mineral | Mineral |
| Mohs hardness | 8.5 | 8.5 |
| Luster | Vitreous | Vitreous |
| Streak | White | White |
| Colors | Green, Red, Purple | Yellow, Green, Brown |
| Crystal system | Orthorhombic | Orthorhombic |
| Specific gravity | 3.7–3.8 | 3.7–3.8 |
| Formula | BeAl₂O₄ | BeAl₂O₄ |
| Found in | Ural Mountains, Russia; Hematita, Minas Gerais, Brazil | Sri Lanka; Minas Gerais, Brazil |
Properties that are the same for both are grayed out.
How to identify alexandrite
- The same stone looks green by a window and reddish under a warm lamp.
- Hardness 8.5 — harder than topaz.
- Ural stones change the most; many newer ones only shift from teal to purple-brown.
Crystal system: Orthorhombic
Full Alexandrite guide →How to identify chrysoberyl
- Hardness 8.5 — harder than topaz.
- Yellow-green, often in heart-shaped or six-pointed twinned crystals.
- Alexandrite looks green in daylight and red under incandescent light.
Crystal system: Orthorhombic
Full Chrysoberyl guide →More comparisons
Frequently asked questions
What is the difference between alexandrite and chrysoberyl?
Alexandrite is a mineral (BeAl₂O₄) with a Mohs hardness of 8.5 and a vitreous luster, usually green, red or purple. Chrysoberyl is a mineral (BeAl₂O₄) with a Mohs hardness of 8.5 and a vitreous luster, usually yellow, green or brown.
How can you tell alexandrite from chrysoberyl?
Ordinary chrysoberyl stays yellow-green in every light. Alexandrite is the color-change variety: green in daylight, redder under a warm bulb.
Could you tell them apart from a blurry close-up?
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