Crystalline Quartz is the general stone which we call Amethyst. As Amethyst it ranges in color from lilac to deep purple. The deeper colors are generally more valuable, and at one time were more valuable than diamonds. The actual crystal hold the properties for Citrineas well. When heated by nature the crystal that is a portion Citriine and a portion amethyst is known as Ametrine. This is a natural and authentic nature made stone found only a few locations. There have been gem dealers known to artificially heat the Amethyst causing it to turn yellow in full or in part then selling the altered stone as Ametrine or Citrine. It is also possible to heat the stone to a lovely shade of green, which is called “green amethyst”. This practice is frowned upon, yet happens still.
Amethyst is mined in Brazil, Uruguay, Bolivia and Argentina, as well as in several African countries. Generally, larger sizes are to be found in South America although Africa is reputed to have the more sought after deeper color in smaller sizes. The darker Amethyst, more often in smaller sizes is also found in Australia.