Amazonite is a name for the blue-green gem variety of microcline feldspar. It’s found only in deposits of pegmatite, and its green color is thought to come from traces of lead and water in the stone. Although amazonite has the same mineral composition as moonstone, another alkali feldspar, its crystal structure is different. (Moonstone is monoclinic and Amazonite, triclinic.) Amazonite can range in shade from a pale blue to verdigris to a deep green. It often shows white streaks or patches, which are actually thin parallel layers of albite .
Amazonite, originally known as amazonstone, is named for the Amazon River, even though it’s never actually been found in the Amazon Basin. Because of the gem’s blue-green color, it was often confused with jade and turquoise, and one theory is that amazonstone got its name when it was mistaken for the jade that came from the Amazon region. A fairly soft stone, amazonite is usually cut as a cabochon.