Fairly new on the market is boulder opal beads. Because opal is so rare it is rarely cut into beads. Boulder opal is opal that has formed in the crevices and cracks of iron or sandstone boulders. Boulder opal is found almost exclusively in Queensland, Australia.
Boulder opal beads will be mostly brown with streaks of opal inside. The brown is the host rock. When polished well these make gorgeous beads!