Is Demantoid hard enough for everyday rings?

Not ideally. At a Mohs hardness of 6.5–7, Demantoid is soft enough to scratch with everyday wear, so it is better suited to earrings, pendants, or occasional-wear rings with protective settings.

How can I tell Demantoid from peridot?

Demantoid and peridot can look alike to the naked eye, but they differ in measurable properties — refractive index (1.88–1.889 for Demantoid), specific gravity (3.81–3.87), and hardness (Mohs 6.5–7). A gemologist confirms the distinction with a refractometer and loupe; the Jewelry Identifier app gives a fast first read from a photo.

* garnet (andradite) gemstone

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

Andradite garnet variety. Dispersion exceeds diamond — exceptional fire. Russian (Ural Mountains) demantoid with horsetail inclusions of byssolite is the historic premium. Discovered 1853.

Published May 30, 2026

Quick facts

Mineral family: garnet (andradite)
Chemical formula: Ca3Fe2(SiO4)3
Mohs hardness: 6.5–7
Refractive index: 1.88–1.889
Specific gravity: 3.81–3.87
Crystal system: cubic
Luster: adamantine
Dispersion: 0.057
Birthstone month: January

Colors

Demantoid is found in green to yellow-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 Demantoid. Hardness, brilliance, and the list of stones it is commonly confused with all give you something concrete to look for.

Scratch resistance: genuine Demantoid sits at Mohs 6.5–7, so it should resist scratching from softer materials — a stone that mars far too easily is suspect.
Brilliance & luster: Demantoid shows a adamantine luster and a refractive index of 1.88–1.889; imitations often look glassier or flatter under the same light.
Density: a real Demantoid has a specific gravity near 3.81–3.87, so it feels heavier or lighter in the hand than many look-alikes of the same size.
Commonly imitated by: peridot, tsavorite. 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 (always untreated)

Treatments are routine for many Demantoid 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 Demantoid

Andradite garnet variety. Dispersion exceeds diamond — exceptional fire. Russian (Ural Mountains) demantoid with horsetail inclusions of byssolite is the historic premium. Discovered 1853.

Sources

Wikidata Q1183057

* Frequently asked

FAQ

Q. Is Demantoid hard enough for everyday rings?: A. Not ideally. At a Mohs hardness of 6.5–7, Demantoid is soft enough to scratch with everyday wear, so it is better suited to earrings, pendants, or occasional-wear rings with protective settings.
Q. How can I tell Demantoid from peridot?: A. Demantoid and peridot can look alike to the naked eye, but they differ in measurable properties — refractive index (1.88–1.889 for Demantoid), specific gravity (3.81–3.87), and hardness (Mohs 6.5–7). 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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