Citrine is a pale yellow variety of quartz. Natural citrine is rare; most of it on the market is actually heat-treated amethyst. In ancient times citrine was known as chryselectrum, a catch-all term that included topaz, citrine, amber, and perhaps even golden beryl. During the Middle Ages citrine was frequently confused with golden topaz. Even in the mid-twentieth century it was often sold as "citrine topaz".