Ametrine is a natural form of quartz. It is a mixture of amethyst and citrine (Amethyst + Citrine = Ametrine) with a range of purple and yellow or sometimes orange. The majority of the commercially available ametrine is from Bolivia, however deposits have been found in other regions in Brazil and India.
Artificial, lower priced ametrine is made by differential heat treating of amethyst and sometimes has the color of Green-yellow or golden-blue which is not known to occur naturally.
