oxides
Citrine
SiO2
- Also known as
- madeira citrineburnt amethyst
- Crystal system
- trigonal
- Hardness
- 7 on the Mohs scale
- Lustre
- vitreous
- Colour
- Pale yellow to brownish orange
- Where it forms
- Genuine natural citrine forms in the same cavities as amethyst but is far rarer, because the conditions that give the yellow defect rather than the purple one are uncommon.
- Chiefly from
- Rio Grande do Sul, BrazilSalamanca, SpainMadagascar
Why it is that colour
Iron, as in amethyst, but in a different oxidation state and a different defect arrangement. Heating amethyst converts one to the other, which is the entire commercial story of this stone.
Safety
No hazard from handling.
Where it comes from
The overwhelming majority of citrine on sale is heated amethyst, mostly Brazilian, and the trade does not generally disclose this. It is not fraud in any meaningful sense — the material is still quartz and the treatment is stable and permanent — but a buyer who believes they have bought a rare natural stone has usually bought a common one that spent time in an oven.
Historical use
Used in Roman jewellery and revived strongly in Art Deco pieces of the 1920s and 30s, where large golden stones were fashionable and cheaply available.
Recorded as history and attributed where possible. That a stone was used for something establishes that people used it, not that it worked.
What is attributed to it, and since when
Yellow quartz appears in classical and medieval sources without being clearly distinguished from topaz, and the names were used loosely for centuries. The modern association with money and abundance — citrine as "the merchant's stone" — is not traceable to those sources and belongs to the New Age literature of the 1970s and 80s.
Described, not endorsed. Dating a claim is not the same as assessing it — but an association that first appears in a book published in 1985 is not an ancient inheritance, whatever the label says. A sincere account of feeling better is compatible with the stone doing nothing — see the placebo effect.
Sold as this, but not
Worth knowing
The tell is the colour distribution. Natural citrine is usually a fairly even pale yellow. Heated amethyst tends to be more saturated, browner or more orange, and often shows a white or clear zone at the base of the crystal where the original amethyst was palest. Very deep reddish-orange "madeira citrine" is essentially always heated.
Worth being clear about what is and is not going on here. Heat treatment is ancient, ubiquitous and disclosed in the gem trade proper. What is unusual is a market that sells the treated stone under a name for the rare untreated one, to buyers specifically told the material's origin matters.
Identity checked against IMA-CNMNC master list, June 2025.