Boulder Opal

Australian Boulder opals are the second most valuable type of opal.
Boulder opals are easily distinguished by their layer of solid brown ironstone left on the back of the stone. Boulder opals, as the name suggests, are mined from large ironstone boulders under the ground. Thin veins of colorful opal forms in cracks and fissures in these boulders. *
*Boulders Down Under
3 products