Citrine - The name citrine refers to a yellow variety of quartz that is often used in jewellery as a decorative gemstone. The name of the mineral comes from its yellow coloration, because citrus is the Latin term for lemon, and thus clearly indicates the color quality of the gemstone. Citrine belongs to the mineral class of quartz crystals and shines with a greasy or glassy luster. The transparency is transparent to translucent, whereby in combination with a special cut on the surface an attractive sparkle becomes possible and makes this mineral an interesting component for different jewellery. The colour of citrine depends on its origin; it can vary between greenish yellow and brownish yellow. The reason for the colour lies in the composition of the citrine, because they contain iron oxide or iron hydroxide, which can be responsible for the colour. Citrines can also be colored by irradiation. Artificial citrines are usually used to make jewellery, as natural stones are very rare. A frequently used, but wrong name for citrine is topaz. In contrast to citrine, topaz is an island silicate.