Is Smoky Quartz hard enough for everyday rings?

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

How can I tell Smoky Quartz from smoky topaz (often actually citrine)?

Smoky Quartz and smoky topaz (often actually citrine) can look alike to the naked eye, but they differ in measurable properties — refractive index (1.544–1.553 for Smoky Quartz), specific gravity (2.65), and hardness (Mohs 7). A gemologist confirms the distinction with a refractometer and loupe; the Jewelry Identifier app gives a fast first read from a photo.

Does Smoky Quartz come in colors other than brown?

Yes. Smoky Quartz occurs in brown, smoky gray, black (morion). Color is driven by trace elements and treatment history, and it is one of the biggest factors in a stone's value.

* quartz gemstone

Smoky Quartz: identification, value, and how to spot a fake

Brown variety of quartz, colored by natural or artificial irradiation. 'Cairngorm' is the historical Scottish smoky quartz. Affordable, easily faceted in large sizes.

Published May 30, 2026

Quick facts

Mineral family: quartz
Chemical formula: SiO2 (radiation-induced)
Mohs hardness: 7
Refractive index: 1.544–1.553
Specific gravity: 2.65
Crystal system: trigonal
Luster: vitreous

Colors

Smoky Quartz is found in brown, smoky gray, black (morion). 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 Smoky Quartz. Hardness, brilliance, and the list of stones it is commonly confused with all give you something concrete to look for.

Scratch resistance: genuine Smoky Quartz sits at Mohs 7, so it should resist scratching from softer materials — a stone that mars far too easily is suspect.
Brilliance & luster: Smoky Quartz shows a vitreous luster and a refractive index of 1.544–1.553; imitations often look glassier or flatter under the same light.
Density: a real Smoky Quartz has a specific gravity near 2.65, so it feels heavier or lighter in the hand than many look-alikes of the same size.
Commonly imitated by: smoky topaz (often actually citrine). 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

irradiation (much market material is artificially irradiated colorless quartz)

Treatments are routine for many Smoky Quartz 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 Smoky Quartz

Brown variety of quartz, colored by natural or artificial irradiation. 'Cairngorm' is the historical Scottish smoky quartz. Affordable, easily faceted in large sizes.

Sources

Wikidata Q1057793

* Frequently asked

FAQ

Q. Is Smoky Quartz hard enough for everyday rings?: A. Mostly. At a Mohs hardness of 7, Smoky Quartz 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 Smoky Quartz from smoky topaz (often actually citrine)?: A. Smoky Quartz and smoky topaz (often actually citrine) can look alike to the naked eye, but they differ in measurable properties — refractive index (1.544–1.553 for Smoky Quartz), specific gravity (2.65), and hardness (Mohs 7). A gemologist confirms the distinction with a refractometer and loupe; the Jewelry Identifier app gives a fast first read from a photo.
Q. Does Smoky Quartz come in colors other than brown?: A. Yes. Smoky Quartz occurs in brown, smoky gray, black (morion). Color is driven by trace elements and treatment history, and it is one of the biggest factors in a stone's value.

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