Swarovski Crystal beads are one of the finest quality crystal beads available, precise and regular in their cut and colour. The Xilion, or bicone, is the most popular, and the most economical, of the range. They add sparkle to jewellery and beadweaving. Because the holes in these beads can be sharp, they can cut through beading threads, so Fireline is recommended for seed beading with crystals, and Flexrite for stringing.