Alexandrite
greenredpurple · Chrysoberyl family
| Also known as | Chrysoberyl (Chrysoberyl family) |
|---|---|
| Colour | Green, Red, Purple |
| Mohs hardness | 8.5 |
| Lustre | Vitreous |
| Streak | White |
| Crystal system | Orthorhombic |
| Cleavage | Distinct on {110}, imperfect on {010}, poor on {001} |
| Fracture | Conchoidal to uneven |
| Chemical formula | BeAl 2 O 4 |
| Specific gravity | 3.5–3.84 |
What is Alexandrite?
The mineral or gemstone chrysoberyl is an aluminate of beryllium with the formula Be Al2O4. The name chrysoberyl is derived from the Greek words χρυσός chrysos and βήρυλλος beryllos, meaning "a gold-white spar". Despite the similarity of their names, chrysoberyl and beryl are two completely different gemstones, although they both contain beryllium and aluminium. Chrysoberyl is the third-hardest frequently encountered natural gemstone and lies at 8.5 on the Mohs scale of mineral hardness, between corundum (9) and topaz (8).
How to identify Alexandrite
- Lustre: Vitreous.
- Hardness: Mohs 8.5 — hard enough to scratch glass.
- Streak: White.
- Habit: Orthorhombic crystal system.
Alexandrite value
Alexandrite is a fine gemstone priced per carat by quality — colour, clarity, cut, carat and origin — not by weight in grams. Typical market ranges:
| Quality | Price per carat |
|---|---|
| Commercial | $300–$2,000 / ct |
| Good | $2,000–$10,000 / ct |
| Fine | $5,000–$20,000 / ct |
| Top | $15,000–$70,000+ / ct |
Ranges cross-validated across two independent research passes against gemstone price guides, 2026-06 — sources: gia.edu, gemsociety.org. Colour saturation, clarity, cut and origin move the price enormously, and treatments or lab-grown stones sell for a fraction — so this is a guide, not an appraisal. Have anything valuable checked by a certified gemmologist. See the full crystal & gemstone value guide.
