Matrix Boulder Opal is a term to describe natural opals within pores, holes, or between grains of the ironstone boulder in which it was formed. This natural process creates stones holding different colors, patterns, and variations. Boulder opals are only found in one part of the world - Queensland, Australia. We love them for their vibrance and unique characteristics—the perfect stone for creating a piece that can't be replicated! Truly mine to market - our opals are sourced directly from the miners and cutters of a small family-run business in western Queensland, Australia. They are mined on a small scale - with a maximum of three people on-site during opal mining season. When a section of the mine is complete, they rejuvenate the land with native seeds local to the area.