Citrine or lemon quartz is the lemon yellow translucent variant of the mineral quartz (SiO₂). Properties Just like the other varieties of quartz, the translucent citrine is a nesosilicate. The yellow color is caused by trace elements, in which divalent and trivalent iron play a role. The crystal system of citrine is trigonal and the hardness is 7. Name: The name citrine is derived from citrus (because of the yellow color). Depending on the colour, the quartz variety was also called Madeira topaz, golden topaz or Bahía topaz in the past, completely incorrectly, because topaz is a completely different mineral. This was probably done to suggest a higher value. Occurrence: The most important sources of citrine are Brazil, Madagascar and the former Soviet Union. Amethyst is often burned and sold as citrine. You can recognise this by brown to black points. Citrine is more valuable than amethyst.