The sizing on these may vary as a result of the production process, optimally they are about 14mm. The dichroic adds such sparkle and depth to the bead which is very difficult for photography. The exact placement and coverage of the dichroic also varies. Available in Rubino, Aqua, Bluino, Acciaio (Steel), Aquamarine (very light Aqua).Dichroic Beads are a great way to upscale your Murano Glass Jewelry.