Citrine is the bright yellow to yellowish orange variety of the mineral quartz. Natural citrine is rare these days. Natural citrine is found near deposits of amethyst or smoky quartz that may have been turned by heat from volcanic activity. Natural citrine has many more hues than commercially heat treated material. Some of the natural colors are described as mandarin orange, madeira red, light yellow lemon quartz and others. Almost all heat-treated material has a reddish tint, whereas the natural specimens do not. Sometimes citrine has a smoky hue and may be called citrine or smoky quartz.