Citrine
Most citrine on the market started its life as low grade amethyst or smoky quartz which has been heated in order to turn its color in yellow.
Natural citrine is mined in Brazil. Supply of citrine of good quality comes from the Brazilian state of Rio Grande do Sul, particularly from the Serra mine, which is producing 300 kilos a month of goods.
The Ira' mine produces an additional 100 kilos a month.