Gem Lab vs At-Home Tests: Which Is Better for Checking If Your Crystal Bracelet Is Real?

At-home tests are enough for most crystal bracelets—a kitchen scale, a scratch test, and a close look at inclusions will catch glass and plastic fakes across the quartz family. A gem lab is worth it only when treatments are invisible to the eye, like heat-treated amethyst sold as citrine.

Last updated: September 10, 2026

By Mara Ellison · Founding Editor, Dusk & Relic Journal

What does a gem lab actually test on a bracelet?

A gemological lab measures refractive index and specific gravity—sometimes supplemented by spectral absorption—to identify a stone's mineral species and any treatments. For clear quartz, the refractive index falls within 1.544–1.553 and the specific gravity reads 2.651 (International Gem Society). Those two numbers alone separate quartz from glass or plastic.

The problem with bracelets: labs test one stone at a time. Every bead needs its own reading, so the combined testing cost for a full bracelet can exceed the price of the piece.

Moss Garden · $95. View this piece’s details →

What can you check at home?

Three tests catch the most common fakes.

The weight test works because quartz has a specific gravity of 2.651—noticeably heavier than water. Weigh the bracelet dry on a kitchen scale, then submerge it and recalculate. Plastic beads land well below that ratio.

The scratch test works because quartz sits at Mohs 7, hard enough to scratch glass. Run a bead gently along a piece of scrap glass. If the bead slides without leaving a mark, the bead is softer than quartz—likely glass or plastic. The USGS lists glass and plastics as common gemstone substitutes, and with 99% of U.S. gemstone consumption supplied by imports, checking beads yourself is more reliable than trusting a distant label.

The inclusion test needs only a phone flashlight. Natural clear quartz shows color zoning and two- or three-phase inclusions—patterns that separate real crystal beads from fakes under magnification. Glass shows perfectly round bubbles instead.

Which fakes does each method catch?

At-home tests catch material fakes; lab tests reveal invisible treatments.

Fake Type	At-Home Test	Gem Lab
Glass posing as quartz	Scratch test (Mohs 7 scratches glass) plus bubble check	Refractive index confirms mineral (quartz: 1.544–1.553)
Plastic or resin	Weight test (quartz SG 2.651 vs lighter plastic)	Precise specific gravity measurement
Heat-treated amethyst sold as citrine	Uniform color may raise suspicion, but not conclusive	Spectroscopy detects treatment
Dyed quartz	Color pooled in surface cracks under magnification	Spectral analysis confirms dye

The dividing line: at-home tests catch material substitution, where glass and plastic are the usual culprits. Lab tests detect invisible treatments—a heated stone looks the same as a natural one to the naked eye. If the question is whether a bracelet's beads are real citrine or glass, the scratch and weight tests confirm the bead is quartz, but only spectroscopy reveals whether the color came from heat treatment.

Moss agate sits at the opposite end—green dendritic inclusions are visible without magnification, so a bracelet like Moss Garden (10 mm, $95) needs no lab to prove the beads are real.

Which stones actually need a gem lab?

Moonstone is one stone where a lab earns its fee. Moonstone has a specific gravity of 2.56–2.59—close enough to some glass compositions that a kitchen-scale test gives ambiguous results. Moonstone also has perfect cleavage in two directions, so a scratch test risks chipping the bead. A lab refractometer identifies moonstone without contact.

I'd send any moonstone bracelet—like Little Planet (10 mm, $95)—to a lab rather than gamble on either home test.

Heat-treated citrine is the other common case. The International Gem Society notes that heat-treated citrine may fade when exposed to further heat (International Gem Society). Knowing whether citrine's color is natural or heated matters for long-term care, and only spectroscopy answers that non-destructively.

Which test should you pick for your bracelet?

One rule covers most situations: if the bead scratches glass and sinks in water the way quartz should, the bead is quartz—no lab needed.

Choose at-home testing for quartz-family bracelets at everyday prices. Frost & Fortune (10 mm, $115) with green phantom quartz shows phantom inclusions under a phone camera. Golden Thread (10.5 mm, $115) with gold rutilated quartz has visible rutile needles inside each bead—proof of natural origin. A multi-stone piece like Happiness Is (11 mm, $90) can be spot-checked stone by stone: citrine at a specific gravity of 2.651, clear quartz beads at Mohs 7.

Choose a gem lab for stones where treatment detection or species identification matters. If the question is whether the color in a quartz bracelet is natural or the result of dyeing, spectroscopy is the only sure answer.

FAQ

Can I test crystal beads without taking the bracelet apart?

Yes. The scratch test and weight test both work with beads still strung. For specific gravity, submerge the whole bracelet and weigh it as one piece—just dry it thoroughly afterward. The inclusion check works the same way, bead by bead under a flashlight.

Will a gem lab damage my crystal bracelet?

Standard gemological tests are non-destructive. Refractive index measurement and specific gravity testing leave no marks. Labs do not use acid or other destructive methods on finished jewelry without your permission.

Is heat-treated citrine still real citrine?

Heat-treated citrine is real quartz—same Mohs hardness of 7, same specific gravity of 2.651. The treatment changes color from amethyst purple to citrine yellow. The mineral is genuine, but the color is artificially produced.

Can synthetic quartz pass a scratch test?

Synthetic quartz has the same hardness as natural quartz and passes the scratch test. But synthetic quartz beads are uncommon. The USGS identifies glass and plastics as the typical gemstone substitutes, not lab-grown quartz.

Does the specific gravity test work on small beads?

Submerging the whole bracelet gives a more reliable specific gravity reading than testing one bead. The more mass on the scale, the more accurate the calculation. A standard kitchen scale is precise enough for a full bracelet.

What if my bracelet looks real but feels too light?

Low weight relative to size is the strongest indicator of plastic or resin beads. Quartz at a specific gravity of 2.651 feels noticeably heavier than plastic at any bead diameter. If a stone bracelet feels as light as an acrylic bangle, the beads are likely not stone.

Should I ask the seller for a certificate instead of testing myself?

A certificate from a recognized lab is useful only if it identifies the specific stones in your bracelet—not just a generic mineral name. A per-stone or per-lot lab report means something. A blanket 'natural crystal' label without per-bead testing is not a substitute for your own checks.