Ametrine is a mixture of Amethyst and Citrine. Our Ametrine is 100% natural and is NOT heat treated. Most of the Citrine sold online is heat treated in a laboratory (You can heat up Amethyst to make Citrine). Generally you can tell with Ametrine that its real when you see only small pockets of Citrine within the Amethyst like the towers we are selling here. The color is also important and should be as shown. We are so certain as to the authenticity, quality, and value of our natural crystals given that we source directly so there are no middlemen to misrepresent the product to us (Such as at the many crystal shows most shops buy from where the vendors disappear the next day). We are our own wholesaler! Various High Quality Natural Crystals available, use the selector to see the size, weight, photo and price of your specific choice.