Crystal Rainbow AB. is a man-made Swarovski® crystal. This bead is semi-translucent and appears as a rainbow, with hues of green, blue, lavender, pink, orange 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.