Is Alexandrite hard enough for everyday rings?

Yes. At a Mohs hardness of 8.5, Alexandrite is durable enough for daily-wear rings; it resists the scratches that everyday surfaces inflict.

How can I tell Alexandrite from synthetic color-change corundum?

Alexandrite and synthetic color-change corundum can look alike to the naked eye, but they differ in measurable properties — refractive index (1.741–1.76 for Alexandrite), specific gravity (3.71–3.75), and hardness (Mohs 8.5). A gemologist confirms the distinction with a refractometer and loupe; the Jewelry Identifier app gives a fast first read from a photo.

* chrysoberyl gemstone

Alexandrite: identification, value, and how to spot a fake

Color-change variety of chrysoberyl. Discovered Russia 1834. Strongest color change in nature ('emerald by day, ruby by night'). Russian Ural alexandrite with strong change commands extreme premiums.

Published May 30, 2026

Quick facts

Mineral family: chrysoberyl
Chemical formula: BeAl2O4 (Cr impurity)
Mohs hardness: 8.5
Refractive index: 1.741–1.76
Specific gravity: 3.71–3.75
Crystal system: orthorhombic
Luster: vitreous
Birthstone month: June

Colors

Alexandrite is found in green in daylight, red in incandescent light (color change). The body color, its saturation, and how evenly it spreads through the stone are among the strongest drivers of value.

How to tell real from imitation

No single test settles it, but a few grounded checks quickly narrow things down for Alexandrite. Hardness, brilliance, and the list of stones it is commonly confused with all give you something concrete to look for.

Scratch resistance: genuine Alexandrite sits at Mohs 8.5, so it should resist scratching from softer materials — a stone that mars far too easily is suspect.
Brilliance & luster: Alexandrite shows a vitreous luster and a refractive index of 1.741–1.76; imitations often look glassier or flatter under the same light.
Density: a real Alexandrite has a specific gravity near 3.71–3.75, so it feels heavier or lighter in the hand than many look-alikes of the same size.
Commonly imitated by: synthetic color-change corundum, synthetic alexandrite. If a deal looks too good, suspect one of these substitutes first.
Fast first read: photograph the stone in the Jewelry Identifier app to estimate the gemstone and its likely value range, then confirm anything important with a gemological lab.

Common treatments

none typically

Treatments are routine for many Alexandrite stones, but they materially affect value and should always be disclosed — an untreated, lab-certified stone commands a clear premium over a treated one.

What to know about Alexandrite

Color-change variety of chrysoberyl. Discovered Russia 1834. Strongest color change in nature ('emerald by day, ruby by night'). Russian Ural alexandrite with strong change commands extreme premiums.

Sources

Wikidata Q258266

* Frequently asked

FAQ

Q. Is Alexandrite hard enough for everyday rings?: A. Yes. At a Mohs hardness of 8.5, Alexandrite is durable enough for daily-wear rings; it resists the scratches that everyday surfaces inflict.
Q. How can I tell Alexandrite from synthetic color-change corundum?: A. Alexandrite and synthetic color-change corundum can look alike to the naked eye, but they differ in measurable properties — refractive index (1.741–1.76 for Alexandrite), specific gravity (3.71–3.75), and hardness (Mohs 8.5). A gemologist confirms the distinction with a refractometer and loupe; the Jewelry Identifier app gives a fast first read from a photo.

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