Is Andalusite hard enough for everyday rings?

Mostly. At a Mohs hardness of 7–7.5, Andalusite stands up to routine wear, though sharp knocks and abrasive dust can still mar it over years of daily use.

How can I tell Andalusite from alexandrite (color-change)?

Andalusite and alexandrite (color-change) can look alike to the naked eye, but they differ in measurable properties — refractive index (1.633–1.644 for Andalusite), specific gravity (3.13–3.2), and hardness (Mohs 7–7.5). A gemologist confirms the distinction with a refractometer and loupe; the Jewelry Identifier app gives a fast first read from a photo.

* andalusite gemstone

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

Strong trichroism shows multiple colors simultaneously from one viewing angle. Different optical phenomenon from alexandrite. Brazilian and Spanish (Andalusia, namesake) sources.

Published May 30, 2026

Quick facts

Mineral family: andalusite
Chemical formula: Al2SiO5
Mohs hardness: 7–7.5
Refractive index: 1.633–1.644
Specific gravity: 3.13–3.2
Crystal system: orthorhombic
Luster: vitreous

Colors

Andalusite is found in yellow-brown to green with strong pleochroism (yellow + reddish-brown + green). 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 Andalusite. Hardness, brilliance, and the list of stones it is commonly confused with all give you something concrete to look for.

Scratch resistance: genuine Andalusite sits at Mohs 7–7.5, so it should resist scratching from softer materials — a stone that mars far too easily is suspect.
Brilliance & luster: Andalusite shows a vitreous luster and a refractive index of 1.633–1.644; imitations often look glassier or flatter under the same light.
Density: a real Andalusite has a specific gravity near 3.13–3.2, so it feels heavier or lighter in the hand than many look-alikes of the same size.
Commonly imitated by: alexandrite (color-change). 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 Andalusite 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 Andalusite

Strong trichroism shows multiple colors simultaneously from one viewing angle. Different optical phenomenon from alexandrite. Brazilian and Spanish (Andalusia, namesake) sources.

Sources

Wikidata Q132568

* Frequently asked

FAQ

Q. Is Andalusite hard enough for everyday rings?: A. Mostly. At a Mohs hardness of 7–7.5, Andalusite stands up to routine wear, though sharp knocks and abrasive dust can still mar it over years of daily use.
Q. How can I tell Andalusite from alexandrite (color-change)?: A. Andalusite and alexandrite (color-change) can look alike to the naked eye, but they differ in measurable properties — refractive index (1.633–1.644 for Andalusite), specific gravity (3.13–3.2), and hardness (Mohs 7–7.5). 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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