Discover the natural beauty of Boulder Opal Cabochons with this AAA gemstone lot featuring mixed designer shapes ranging from approximately 18 mm to 25 mm. Mined in Australia, these premium cabochon stones combine earthy host rock patterns with brilliant flashes of opal color, creating truly distinctive natural gemstones. The polished flat-back finish makes these loose gemstones an excellent choice for handcrafted jewelry, bezel settings, pendants, and one-of-a-kind designer pieces.