Australian Boulder Opals are created when opals fill cracks and crevices in ironstone boulders. Because the veins of color are so thin, when the opal is mined and cut the cutters leave the ironstone on the back of the opal to form a full-sized stone. Leaving the ironstone included in the gem cut also gives the polished gemstone extra hardness and stability which gives Boulder Opals a hardness of 5.5-6.5 on the Moh’s Hardness Scale. Due to the dark backing provided by the ironstone, Boulder Opals generally have a dark body tone which creates a visual effect similar to a black opal. The gemstone is also unique because of the irregular and striking pattern that form between the contrast of the opal and the ironstone host rock.
This pair of Australian Boulder Opal earrings are mounted on 18K rose gold. Each opal is unique in its cut as well as the captivating pattern within the stone as the opal runs through the ironstone host rock, which has a tiger’s eye like look to it. The mounting on which the opals are set have been given an organic hammered finish that give the earrings a natural look as though the gold is apart of the gemstone itself. The hooks from which earrings hang are given a contrasting polished finish on the main body that attaches to the mounting of the opal via jump ring.