When Amethyst is subject to extreme heat, it changes colour and is known as Citrine. This can occur naturally if the crystal was formed close to a heat source - volacano etc. Ametrine is a stone that is on the change, showing the colours mainly of Amethyst, but often with the hint of the amber of citrine.
On an emotional level, Ametrine brings clarity, concentration and the ability to think things through.
Physically:Ametrine is a good blood cleanser, boosts the immune system and is believed to be beneficial in the treatment of Chronic Fatique Syndrome.