How Can I Tell If a Citrine Gemstone Is Genuine?

You can tell whether a citrine gemstone is genuine by testing it against three quartz benchmarks: Mohs 7 hardness, 2.651 specific gravity, and a refractive index of 1.544–1.553. Any stone that fails one of those measurements is not citrine, though a stone that passes all three could still be heat-treated amethyst rather than naturally yellow citrine.

Last updated: September 5, 2026

By Mara Ellison · Founding Editor, Dusk & Relic Journal

Quick answer

Citrine is quartz, and the fastest way to verify any citrine stone is to test whether it passes the standard quartz benchmarks. Mohs hardness sits at 7. Specific gravity is 2.651. Refractive index falls between 1.544 and 1.553 (International Gem Society).

The rule worth memorizing: if a stone fails the quartz test, it is not citrine.

Glass and plastic imitations, which the USGS lists as common gemstone substitutes, fail at least one of those measurements. The harder problem is heat-treated amethyst sold as citrine. Heat-treated amethyst is also quartz, so it passes every quartz benchmark. Telling natural citrine from heated amethyst requires examining internal features like color zoning, not the hardness or density tests.

Sunstruck · $115. View this piece’s details →

What numbers define real citrine?

Three measurements separate quartz from non-quartz, and citrine is quartz. The table below shows citrine's values alongside clear quartz — the numbers are identical because both belong to the same mineral family.

Property	Citrine	Clear Quartz (Rock Crystal)
Mohs hardness	7	7
Specific gravity	2.651	2.651
Refractive index	1.544–1.553	1.544–1.553

Sources: IGS — citrine, IGS — quartz.

This overlap is why the quartz test works. A stone labeled citrine must hit these numbers. A stone that misses one is not quartz and therefore not citrine.

What gets passed off as citrine?

The USGS Mineral Commodity Summaries (February 2026) lists glass and plastics among the materials frequently substituted for natural gemstones. U.S. net import reliance for gemstones stood at 99% of apparent consumption in every year from 2021 through 2025, so most gemstone material sold domestically passes through multiple intermediaries before reaching a buyer.

Under magnification, genuine quartz shows internal features — color zoning, phase inclusions (two-phase and three-phase), negative crystals — documented by the International Gem Society. A stone with no visible internal features under magnification is worth checking against the quartz benchmarks.

When does the quartz test not help?

Here is the exception to the rule: heat-treated amethyst is also quartz. An amethyst crystal heated until the color shifts to yellow still passes every quartz benchmark (Mohs 7, SG 2.651, RI 1.544–1.553). The crystal structure does not change during heating. The quartz test catches glass and plastic. The quartz test does not distinguish natural citrine from heated amethyst.

The International Gem Society notes that heat-treated citrine stones may fade when exposed to heat. Fading after heat exposure is one signal, though not a test most buyers would run on a stone they already own.

What should I check when buying a citrine bracelet?

A bracelet with multiple beads gives you several stones to compare side by side. Slight bead-to-bead variation in color or clarity is normal for natural quartz. When every bead on a strand looks perfectly uniform, run the quartz benchmarks before assuming natural origin.

I'd look for bracelets that pair citrine with other quartz varieties, because a known quartz bead next to the citrine acts as a built-in reference point. The Sunstruck (8 mm, $115) pairs citrine in raw nugget form with clear quartz beads. The Dusk & Citrine (10–11.5 mm, $95) combines citrine with amethyst and phantom quartz — all quartz varieties — making comparison across stones straightforward.

FAQ

Is heat-treated amethyst still real quartz?

Heat-treated amethyst passes every quartz benchmark (Mohs 7, SG 2.651, RI 1.544–1.553) because amethyst is quartz. The color changed during heating; the crystal structure did not.

Will heat-treated citrine fade over time?

The International Gem Society notes that heat-treated citrine stones may fade when exposed to heat. If long-term color stability matters, asking whether a stone has been heat-treated before purchasing is worth the effort.

Can a scratch test alone confirm citrine is genuine?

A scratch test confirms that a stone reaches Mohs 7 hardness, which rules out glass and most plastics. A scratch test cannot confirm the stone is specifically citrine rather than another quartz variety, and it will not detect heat treatment.

Why is citrine called the merchant's stone?

In crystal lore, citrine is traditionally called the merchant's stone — a talisman long associated with prosperity and sunny self-belief. The name comes from folk tradition, not from any measured physical property of the stone.

What refractive index should genuine citrine show?

Genuine citrine shows a refractive index between 1.544 and 1.553, matching all quartz varieties. A gemological refractometer reads this value. Any stone reading outside that range is not quartz.

Are glass imitations of gemstones common?

The USGS lists glass and plastics among substitutes frequently used in place of natural gemstones. U.S. net import reliance for gemstones was 99% of apparent consumption in every year from 2021 through 2025, meaning nearly all gemstone material sold in the U.S. is imported.

What internal features should I look for in real citrine?

The International Gem Society documents color zoning and phase inclusions (two-phase and three-phase) as natural internal features of quartz, along with negative crystals. A citrine stone with no visible internal features under magnification warrants further testing.

Does citrine's color help identify whether the stone is genuine?

Color alone does not confirm authenticity. The quartz benchmarks — hardness, specific gravity, refractive index — are measurable properties independent of color. A gemological lab examining these properties along with internal features provides more reliable identification than any visual color judgment.