Beads of opals are very popular especially 8-12 mm sizes.
Opal beads are mainly from boulder opal fields or matrix opal as opal has to be cut in block first than on lapidary equipment to shape opal round and laser to drill hole.
Boulder opal rough with veins are good for making beads. It is hard tog et full colour beads except for crystal opal .Black opal potch faceted is also good for making beads