Dione® large-hole beads are ideal for customized bracelets and necklaces and slide easily over cord and chain. Designed with cat's eye glass and silver-plated brass grommets, each bead has a 4.5mm to 5mm hole. Cat's eye glass is a manmade fiber optic glass that refracts light in a way reminiscent of the oblong center of a cat's eye. This center appearance of movement is caused by chatoyance, which is defined as changeable luster or shine. Beads are machine-cut for consistency in size and shape. Colors may vary.