Amazonite (sometimes called Amazon stone) is a rare blue-green variety of microcline (a feldspar mineral) used as a semiprecious stone. Its brilliant color was once thought to be caused by copper, but now is attributed to the presence of lead or possibly iron. Amazonite is an opaque stone, often found with white, yellow or gray inclusions and a silky luster or silvery sheen. Even when polished, amazonite beads maintain a somewhat raw, natural texture that makes this pale blue-green stone even more appealing to many people. Rainbow amazonite beads, sometimes called black amazonite, offer a wider color range than our other semiprecious amazonite beads, displaying not just shades of pale sea-mist blue-green, but also gray, black, brown, yellow, and rust. Find out more about amazonite in our gemstone index.