How Much Is Ametrine Worth?
The natural two-in-one quartz that splits amethyst purple and citrine gold across a single stone — affordable, durable, and almost entirely from one Bolivian mine.
Ametrine is one of the few gemstones that shows two distinct colours at once, side by side, in a single untreated crystal: the violet of amethyst meeting the warm gold of citrine, divided by a boundary that can be knife-sharp or softly graded. Both zones are the same mineral — quartz — coloured by iron in slightly different oxidation states, a difference set during crystal growth by tiny variations in temperature. Cut to display both halves, it is an unmistakable stone, and one that buyers either love on sight or pass over.
It is also refreshingly honest to price, because the supply story is unusually simple. Virtually all natural gem-quality ametrine on the market comes from a single source: the Anahí mine in eastern Bolivia, near the Brazilian border. That concentration gives the stone a clear origin narrative, but it does not make it expensive — the mine produces steadily, quartz is abundant, and ametrine sits firmly in the affordable, everyday end of the coloured-stone world.
Key takeaways
- Ametrine is natural bicoloured quartz — amethyst and citrine zones in one crystal, not a treatment or a blend of two stones.
- Colour contrast and the boundary drive value. Vivid purple against rich gold, with a clean split, outranks pale or muddy zoning.
- Cut matters more than usual. The lapidary must orient and shape the stone so both colours show face-up in balanced proportion.
- Almost all natural gem ametrine is Bolivian, from the Anahí mine; a credible seller can usually name the source.
- Lab-grown ametrine exists and is cheap. The concern is disclosure — synthetic material sold at natural prices.
What ametrine actually is
Ametrine is a variety of macrocrystalline quartz, the same species that gives us amethyst, citrine, rock crystal and smoky quartz. Its defining feature is colour zoning: within one crystal, some sectors are coloured the purple of amethyst and others the yellow-to-orange of citrine. Both colours come from trace iron, but the two zones differ in how that iron is arranged and oxidised, which in turn reflects small temperature differences across the growing crystal. Nature, in effect, records a temperature gradient as a colour boundary. The trade also calls the stone trystine or, after its origin, bolivianite.
Because it is quartz, ametrine is a practical jewellery stone: Mohs 7, no cleavage to speak of, and generally free of the fragility that limits softer collectors’ gems. It takes a bright polish, is usually eye-clean, and is available in large sizes at low cost, which is why it is a favourite of lapidary artists who cut it into bold, faceted designs to play the two colours against each other.
How it is valued
Four factors set the price, roughly in this order. The strength and contrast of the two colours comes first: the most desirable stones pair a saturated purple with a warm, golden citrine, each colour distinct rather than washed-out or brownish. Second is the boundary and balance — whether the split is crisp and roughly even, or lopsided and muddy. Third is the cut, which matters more here than in almost any other gem: because the rough is zoned, the cutter must orient and shape the stone so both colours appear face-up in pleasing proportion, and good fancy cutting can lift an ordinary crystal noticeably. Fourth is size and clarity: quartz grows large and clean, so buyers can expect eye-clean stones, and price per carat climbs only modestly with size compared with the steep size premiums of rarer gems described in our guide to how gemstones are graded.
Typical fair prices
| Grade | Indicative fair price | Notes |
|---|---|---|
| Commercial, pale or muddy | $5–$15 per ct | Weak colours or a blurred, lopsided boundary |
| Good contrast, clean cut | $20–$40 per ct | Distinct purple and gold, balanced split, eye-clean |
| Fine large, vivid, artist-cut | $50–$100+ per ct | Strong saturation, precise fancy cut, larger sizes |
| Lab-grown ametrine | A few dollars per ct | Legitimate if disclosed; a problem only when sold as natural |
These are Fair Carat’s synthesis of observed dealer and lapidary listings, not survey data. Ametrine is inexpensive enough that cutting quality and size, rather than rarity, tend to decide where a given stone sits within these ranges.
Watch-outs
- Undisclosed synthetic ametrine. Lab-grown quartz can be produced with amethyst-citrine zoning and costs a few dollars a carat. It is a legitimate product when labelled; the problem is synthetic material sold at natural prices. For a valuable purchase, ask for disclosure in writing.
- “Ametrine” that is really heat-treated amethyst. Partly heating amethyst can drive some zones to citrine colours, producing a two-tone quartz. It is not the same as natural Anahí ametrine, and the distinction should be disclosed.
- Buying it as a substitute for amethyst or citrine. Ametrine is its own thing. If you want a single, even purple or gold, buy amethyst or citrine; ametrine is worth paying for only when you actually want the two-colour split.
- Overpaying for “rare” claims. Ametrine is genuinely single-source but not genuinely scarce. Treat steep “investment-grade” pricing with caution.
- Poor cutting that hides the effect. A stone cut without regard to its zoning can show mostly one colour face-up, wasting the whole point of the gem.
For the mineralogy of ametrine and its Bolivian origin, see the GIA gem encyclopedia and Wikipedia. If you want a report confirming natural origin and no undisclosed treatment, see our guide to gemstone treatments and disclosure.
Buy it for the split — judge colour contrast and cut.
A good ametrine earns its price on vivid, balanced two-tone colour and a cut that shows both halves face-up. Ask the seller about origin and whether the stone is natural or lab-grown.
Browse ametrine at Minerals Kingdom →
FAQ
Is ametrine a natural stone or is it treated?
Gem ametrine from the Anahí mine in Bolivia is natural — the two colours form during crystal growth. Lab-grown ametrine and heat-treated two-tone amethyst also exist, so for a significant purchase it is worth asking the seller to confirm the stone is natural and untreated.
Why does ametrine show two colours?
Both zones are quartz coloured by trace iron, but the iron is in slightly different states in the amethyst and citrine sectors. Those differences are set by small temperature variations as the crystal grows, so the stone effectively records a temperature boundary as a colour boundary.
Is ametrine expensive?
No. It is one of the more affordable coloured gems, typically single-digit to low double-digit dollars per carat, with only fine, large, well-cut stones reaching $50–$100 or more per carat. Its appeal is visual drama and durability, not rarity.
Where does ametrine come from?
Almost all natural gem ametrine comes from a single deposit, the Anahí mine in eastern Bolivia. That single-source origin is part of the stone’s story, though it does not make the material scarce or costly.
Is ametrine durable enough for rings?
Yes. At Mohs 7, with no significant cleavage, ametrine is durable enough for everyday jewellery, though like all quartz it benefits from sensible care and protection from hard knocks and abrasion over time.
How is ametrine different from amethyst or citrine?
Amethyst is single-colour purple quartz and citrine is single-colour yellow-to-orange quartz. Ametrine is the natural combination of both in one crystal. Buy ametrine when you specifically want the two-tone effect, not as a cheaper stand-in for either single colour.
More value guides
Sources
GIA gem encyclopedia — ametrine, quartz varieties and colour zoning. Wikipedia — ametrine and the Anahí mine. Observed dealer and lapidary listings for the price data points. All price figures are indicative Fair Carat synthesis, not survey data.
Independent gem-value research. We don’t sell stones and sellers can’t buy a better verdict.
Informational only — not a formal appraisal. For insurance or resale, get a certified appraisal.