Blue Green AB. is a man-made Swarovski® crystal. This bead is semi-translucent and appears blue, with hues of green, blue, lavender, pink and you may even get some yellow. It is absolutely gorgeous! Swarovski's AB effect, named for aurora borealis (the northern lights), is a term for crystal stones that have a highly iridescent surface. Created by Swarovski in 1955 in collaboration with Christian Dior. Each ring is wrapped in German Style wire and can be made in any size, from 2-13, in whole or half sizes.