Natural or heated citrine: how to know what you are buying
Most citrines on the market are heated amethyst. What that means, the colour signs, misleading names (topaz, lemon quartz) and the right questions to ask.
Key points
| Nature | Yellow to brownish-orange variety of quartz (SiO2), hardness 7, density about 2.65 |
|---|---|
| Natural citrine | Rare: pale yellow to orange-yellow, sometimes yellow-green |
| Commercial citrine | Most often heated amethyst (or smoky quartz) |
| Temperature | Amethyst loses its violet colour above about 200 to 300 °C and can turn yellow, orange or brown |
| Main source | Brazil (Rio Grande do Sul, Minas Gerais), but also Madagascar, Uruguay, Zambia, Russia, Bolivia |
| Misleading names | “Golden topaz”, “Madeira topaz”, “lemon quartz” |
A rare stone in its natural state
Citrine is a variety of quartz coloured yellow by small amounts of iron (the exact cause of the colour is still debated: colour centres linked to aluminium or to iron impurities, depending on the research). It is rare in nature. Its natural colour ranges from very pale yellow to honey yellow, sometimes with a green or smoky tint. The word comes from the Latin citrus (lemon).
Because demand is very high, most of what is sold as “citrine” comes from heated amethyst. Brazil is the main source of raw material, in the form of large amethyst geodes. The iron present in amethyst changes state with heat: the violet colour disappears and the stone becomes yellow, orange, sometimes reddish or brown. When it is very orange with red glints, it is called Madeira citrine (or “madeira”). A very dark brownish-red shade is sometimes called “burnt amethyst”.
The GIA, the American gemological institute, puts it plainly: natural citrine is rare, and most commercial citrine is heated amethyst. Under the strict definition used by mineralogists, a heated amethyst is therefore not “true” citrine, but it is genuine quartz, and the treatment is old and common. The problem is not the heating, but the lack of information.
The table of signs
| Sign | Natural citrine | Heated amethyst or smoky quartz |
|---|---|---|
| Colour | Pale yellow to honey yellow, sometimes greenish; soft shade | Strong yellow, true orange, or red-orange; very uniform |
| Variation | Lighter or smokier zones within the same crystal | Even colour throughout the crystal; sometimes white or very pale zones |
| Dichroism | Weak, can be observed with suitable equipment | Absent in heated amethyst (requires a gemmologist's examination) |
| Shape of pieces | Single crystals or small clusters, rarely large geodes | Large very orange druses (clusters of crystals): these generally come from heated amethyst geodes, according to mineral dealers |
| Smoky tint | Brownish-yellow tint, never clear red-orange | Heated smoky quartz: can resemble citrine but retains its dichroism |
These signs are tendencies, not proof. Heating leaves no visible trace to the naked eye on a cut stone, and even a laboratory may hesitate in some cases.
Simple, safe tests
- Read the listing. Look for “natural citrine”, “heated citrine”, “heated amethyst” or “citrine quartz”. A description that just says “citrine” with no further detail is the most common, and the least informative.
- Look at the colour in daylight. A very saturated golden yellow or a deep orange with red glints points to heating. A pale yellow, slightly smoky stone points to natural material.
- Look under a loupe. Citrine, like all quartz, shows irregular inclusions (veils, feathers, fluid cavities) but no round bubbles. Round bubbles indicate yellow glass.
- Compare the colour in the fractures. A dye concentrates in the cracks; natural or heated citrine has the same shade throughout the mass.
- Look at a whole batch. Hundreds of pieces of an identical orange are almost certainly heated; this is not abnormal if it is disclosed.
Avoid. Heating a stone at home “to see” is dangerous (quartz can shatter) and ruins the piece; no acid, flame or scratching.
What these tests do not prove. They do not reliably separate natural citrine from heated amethyst. Only a laboratory can provide solid evidence, and even it may remain cautious. For a large, valuable piece, do not rely on colour alone.
Misleading names and other yellow stones
| Name | What it really is |
|---|---|
| Golden topaz, Madeira topaz, citrine topaz | Old trade names for citrine; the term “topaz” is misleading, because topaz is a different, harder mineral (hardness 8) |
| Lemon quartz | Clear (colourless) quartz that has been irradiated, vivid yellow to yellow-green; artificial colour, but it is quartz |
| “Madeira” citrine | Very orange citrine from heated amethyst, with red glints |
| Prasiolite | Green quartz, often obtained by heating amethyst; another treatment of the same mineral |
| Ametrine | Bicoloured violet and yellow quartz; occurs naturally (Anahí deposit, Bolivia) but is also treated or synthetic |
| Yellow glass, yellow “crystal” | Imitation; round bubbles are possible |
| Synthetic citrine | Quartz made in the laboratory; synthesis trials have not reproduced the natural colour or dichroism, according to Wikipedia |
What the law says and what to ask
In France, decree no. 2002-65 of 14 January 2002 requires disclosure of dyeing, irradiation and several other treatments. But its Article 3 exempts a heat treatment from disclosure when it leaves no residue visible under a 10x loupe: this is the case for heated amethyst. According to one legal commentary, this exception is criticised as outdated. The consequence is simple: many labels say nothing, even though the stone has been heated. An honest shop discloses it; that is what we commit to doing when our supplier tells us (see our commitments).
Before buying, ask these questions:
- Is the piece natural citrine, heated amethyst or heated smoky quartz?
- Is the colour natural, heated, irradiated or dyed?
- What is the origin (Brazil, Madagascar, other)?
- If the piece is presented as a “citrine cluster”: does it come from an amethyst geode?
Care and symbolism
Citrine, natural or heated, is quartz: hardness 7, good resistance to water and gentle cleaning. The only precaution is strong light: prolonged exposure to sunlight can fade some pieces, especially dyed or irradiated ones. Knocks on an edge can chip it. See the cleansing guide.
Traditional symbolism (sun, optimism, abundance) does not depend on gemmological status: see the citrine profile and “How to recognise a real citrine”. For the general framework, see how to read a label.
Frequently asked questions
Is commercial citrine natural?
Most often it is heated amethyst, which turns yellow to orange. It is genuine quartz, but it is not natural citrine, which is rare.
Is a very orange citrine necessarily heated?
Almost always. Natural citrine is more often pale yellow to honey yellow. A true orange with red glints (Madeira citrine) usually comes from heated amethyst.
Is heated citrine of lower quality?
Not necessarily: it is hard, durable quartz. The difference lies in rarity and in the honesty of the label, not in durability.
Is golden topaz citrine?
The name is misleading. It is an old trade name for citrine, whereas topaz is a different and harder mineral.
Can I heat an amethyst myself to transform it?
No. It is dangerous (the stone can shatter, the heat required is high) and the result is unpredictable.
Also read
The meanings mentioned belong to tradition and symbolism. They are neither promises of results nor medical advice. Back to Recognizing real stones.