These small 4mm crystal beads have a .6mm hole with a rounded edge to reduce wear on your stringing material. These crystal glass beads are perfect for dash of color in a necklace design or bracelet project Swarovski's brand of Austrian crystal is famed for its precision shape and brilliant color. Black Diamond Bicone Beads offer a pale, greenish-gray sparkle in your next jewelry design. Adding these Swarovski Bicone Beads to your next jewelry project creates an unmistakable sign of authenticity and elegance.