What Is Citrine — and Why Is Most of It Not Natural?

Citrine is the yellow-to-orange variety of quartz, colored by trace iron impurities within the crystal. Naturally occurring citrine is genuinely uncommon — the largest natural deposits are in Brazil, and even there it's a small fraction of total quartz output.

Because natural supply is so limited, most citrine sold commercially is amethyst or smoky quartz that has been heat-treated to permanently shift the iron's oxidation state toward yellow-orange. This is a standard, accepted practice in the trade, but it's worth knowing: heat-treated citrine tends to have a uniform, saturated orange color, while natural citrine is usually paler and more muted, sometimes with a slightly smoky cast.