Ametrine is a gem type many haven’t heard of but should definitely consider as it's beautiful, unique, and uncommon. An incredibly rare form of quartz, Ametrine is formed when Citrine and Amethyst combine during formation. There are actually very few occurrences of yellow gemstones in nature and while Amethyst is widely available Citrine isn't. With limited occurrence of Citrine the appearance of Ametrine is even rarer. Good ways to use ametrine gemstones: Ametrine is a great gemstone to use for any jewelry design purpose. It is durable inexpensive and available in a variety of shapes and sizes. Earrings, necklaces, rings, pendants, and bracelets are all wonderful designs for this unique and rare gemstone.