Citrine is a yellow gemstone belonging to the quartz family. Like all types of quartz, it has a hardness of 7 on the Mohs scale. Its name comes from the French word citron, meaning "lemon." Its color can range from pale yellow to orange. The yellow hue is due to iron (Fe3+) acting as a chromophore. It was classified within the quartz family in the 16th century. Citrine was formerly used as a protective talisman against the plague, impure thoughts, and skin problems.