Scratch Test vs Loupe Check: Which Is Better for Telling if Your Crystal Bracelet Is Real?

A loupe is more reliable than a scratch test for verifying crystal bracelets. Scratch testing only confirms hardness — quartz-family stones register Mohs 7 — while a loupe reveals internal features like color zoning and two-phase inclusions that glass substitutes cannot replicate.

Last updated: September 8, 2026

By Mara Ellison · Founding Editor, Dusk & Relic Journal

What does a scratch test actually prove?

A scratch test measures one property: where a stone falls on the Mohs hardness scale. Clear quartz and citrine both sit at Mohs 7 (International Gem Society). A bead at Mohs 7 hardness will resist softer materials, confirming the stone is not soft plastic. The problem: dozens of minerals share the Mohs 7 range, and a scratch test cannot tell you whether a blue-green bead is real aquamarine or a glass imitation. Hardness alone cannot identify which mineral a bead is.

Damage is the other concern. Moonstone has perfect cleavage in two directions, so pressing a hard point against a moonstone bead can split the stone along an internal plane. A scratch test on quartz is survivable; a scratch test on a cleavage-prone stone can destroy the bead.

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What does a loupe show that hardness misses?

A loupe shows internal structure, and natural structure is the one feature a fake cannot copy. Natural clear quartz contains color zoning, two- and three-phase inclusions, and negative crystals under magnification (IGS). A bead labeled quartz that shows none of these features deserves scrutiny.

U.S. net import reliance for gemstones sat at 99% from 2021 through 2025 (USGS Mineral Commodity Summaries 2026), and the same report lists glass and plastics as the most common substitutes for natural gemstones. Since real quartz and glass beads differ most in their internal features, a loupe catches substitutions that a surface scratch cannot.

How do the two methods compare?

The loupe wins on safety and specificity; the scratch test is faster but limited to hardness.

	Scratch test	Loupe
Measures	Hardness (Mohs scale position)	Internal structure (inclusions, zoning)
Quartz (Mohs 7)	Bead survives; confirms Mohs 7 hardness	Reveals color zoning, two-phase inclusions, negative crystals
Moonstone	Risky — cleavage in two directions can split the bead	Safe; no contact pressure
Glass detection	By hardness difference only	By absence of natural mineral inclusions
Damage risk	Surface mark or cleavage split possible	None

Which stones survive a scratch test?

Quartz-family stones handle a scratch test without structural risk. Clear quartz, citrine, amethyst, smoky quartz — every quartz variety sits at Mohs 7, making the beads hard enough to withstand a scratch test without fracturing. A piece like Dusk & Citrine (10–11.5 mm, $95) pairs amethyst and citrine with phantom quartz — all quartz varieties, all Mohs 7.

Stones with cleavage pose a different risk. Moonstone's specific gravity of 2.56–2.59 can be checked by water displacement — no contact, no cleavage risk. For moonstone, a loupe or a density test is always safer than dragging a hard point across the surface.

I'd default to a loupe for any mixed-stone bracelet, because one accent bead in the strand might be cleavage-prone even if the rest are quartz. For a confirmed all-quartz piece, a scratch test works as a quick backup.

Which method should you pick?

Choose the scratch test if the bracelet is confirmed all-quartz. Quartz at Mohs 7 is hard enough that a scratch test will not fracture the bead. A strand like Frost & Fortune (10 mm clear quartz and green phantom quartz, $105) is entirely quartz-family and handles the test safely.

Choose a loupe if the bracelet contains mixed minerals, stones you cannot identify, or any feldspar-family bead. A loupe works across every stone type without risk. For a piece mixing quartz with non-quartz materials — like Tide Chime (6–10 mm aquamarine and freshwater pearl, $75) — the loupe covers every bead safely. When both methods leave doubt, whether a gemological lab is worth the visit depends on the piece's value and how much certainty you need.

FAQ

Does a scratch test work the same way on every crystal?

No. Quartz-family stones — clear quartz, citrine, amethyst — all register Mohs 7 and handle the test without damage. Moonstone has perfect cleavage in two directions, so a scratch test can split a moonstone bead along a natural weakness. Always confirm the stone type before running any contact test.

Can heat-treated citrine still pass a scratch test?

Yes. Heat treatment does not change citrine's Mohs 7 hardness. Under a loupe, heat-treated citrine may show unusually uniform color compared to the natural zoning of untreated quartz. Heat-treated citrine can also fade when exposed to prolonged heat.

What inclusions should real quartz show under a loupe?

Natural clear quartz typically shows color zoning along with two-phase and negative crystal inclusions. These features form during crystal growth and are absent in glass. A bead that lacks these growth features is worth testing further.

What if my bead shows no inclusions at all?

Absence of inclusions in a bead labeled quartz is a red flag. The USGS notes that glass and plastics are commonly substituted for natural gemstones, and glass lacks the growth features typical of natural quartz. A follow-up density check — quartz has a specific gravity of 2.651 — can add a second data point.

Can I check specific gravity without unstringing the bracelet?

Specific gravity requires weighing a bead in air and in water, so the bead needs to be off the string for an accurate reading. Clear quartz has a specific gravity of 2.651, and moonstone sits at 2.56–2.59. For beads still on a bracelet, a loupe is the more practical first check.

What does refractive index tell me that hardness and a loupe don't?

Clear quartz has a refractive index of 1.544–1.553, which helps separate quartz from materials of similar hardness. Measuring refractive index requires a refractometer — standard in gemological labs but uncommon at home. For a home check, a loupe is the more accessible starting point.

How common are glass substitutes in crystal jewelry?

The USGS lists glass and plastics as the primary substitutes for natural gemstones. With U.S. net import reliance for gemstones at 99% from 2021 through 2025, most crystal beads pass through multiple international middlemen before reaching a buyer, and each handoff is a point where substitution can happen.