Amazonite Mineral information, data and localities.Name Named in 1847 by Johann Friedrich August Breithaupt for an unspecified type locality area "near" the Amazon River. A variety of Microcline. A green to bluegreen variety of Kfeldspar, usually microcline, but sometimes applied to orthoclase. The color is usually caused by an elevated content of Pb (up to 1.2% PbO, see list of references).Amazonite WikipediaAmazonite, also known as Amazonstone, is a green tectosilicate mineral, a variety of the potassium feldspar called microcline. Its chemical formula is KAlSi3O8, which is polymorphic to orthoclase. Its name is taken from that of the Amazon River, from which green stones were formerly obtained, though it is unknown whether those stones