Historically applied to naturally yellow quartz,
the name "citrine" now also refers to heated amethyst
The name"citrine" comes from the French citron, meaning "lemon," and has been used in reference to quartz that has a somewhat dark yellow color. Naturally colored citrine has the dark, blackish color seen in the photograph on the next page. However, this material has never been particularly popular as a gemstone.

In 1883, the Brazilians discovered by chance that heating amethyst (purple quartz) caused its color to change to a vivid yellow. Because this color resembles that of the gemstone topaz, this material was mistakenly called "golden topaz" for many years. However, topaz is a completely different mineral from quartz. Today, heated amethysts such as those in the earrings shown below are called "citrine" and are used as a jewelry material.

Most amethysts will alter to citrine when heated to approximately 450°C (840°F). This heating is considered an acceptable treatment that brings out the latent beauty of a stone. Similarly, most aquamarine is green beryl that has been treated at temperatures nearing 420°C (790°F). In both cases, the treatment is permanent, and once the color has been altered it will not revert back to the original.
The German city of Idar-Oberstein, located some 120 kilometers (72 miles) west-southwest of Frankfurt, has long been associated with citrine and amethyst. Chalcedony, a variety of quartz, was discovered in the area in 1497. Later, amethyst was also discovered there, and the polishing of both of these materials continued. A period of decline followed the playing out of the chalcedony mines, but in the 1830s, settlers from Idar who had emigrated to Brazil began sending chalcedony rough back home, causing a resurgence of activity. Motors were used in the polishing process from about 1900, and the export of chalcedony, amethyst, and citrine to various European cities, such as St. Petersburg in Russia, flourished. Even now there are about 400 lapidaries (stone cutters) in Idar, and it is considered to be among the major colored-stone polishing centers of the world. Along with amethyst and chalcedony, citrine is one of the gemstones that have helped sustain the city of Idar.
Earring, Gold
Citrine 2 pc
Total 12.61 ct
US $2,500