Citrine is a type of quartz, a mineral widely distributed in the earth's crust. Its yellow to golden color is due to the presence of traces of iron in its crystal structure. Specimens of natural Citrine are relatively rare. Most Citrines available on the market are actually amethysts or smoky quartz heated to a yellow hue. This semi-precious stone is mainly found in Brazil, but also in France, Spain and Russia. It has a hardness of 7 on the Mohs scale, making it strong enough to be used in jewelry. Citrine is also used as a gem in the jewelry industry.
