Known for its lively, flaming color displays, boulder opal is in high demand by collectors and jewelry designers. As opposed to cut opal gems, boulder opal features small opal veins running through its matrix. The precious opal's rainbow of colors make a dramatic contrast to the rich earthy reds and browns of the host rock, creating a one-of-a-kind display.
- Optical Properties
- Characteristic Physical Properties
- Chemistry & Crystallography
Boulder Opal Colors
Precious Opal, Natural Opal Type 2, Yowah Opal
Countries of Origin
Unknown; Mexico; Australia
Boulder opals are small opal veins running through matrix, the host rock. The precious opal's myriad of colors creates a breathtaking display in contrast to the rich earthy reds and browns of the host rock. The result is a one-of-a-kind stone that is sought after by gemstone and jewelry lovers for the promise of a rainbow of beauty. Don't let its beauty fool you: opal is one tough stone, it's quite hard (5 - 6 ½ on the Mohs scale) and wonderfully wearable.
More About Boulder Opal
We have evidence that opals have been around since at least 200 B.C., so they have plenty of folklore that has grown around their beauty. Some we like include the Arabian belief that opals fall from heaven in flashes of lightning; the Oriental belief that opal was the stone of hope; and from the ancient Greeks, the belief that it bestowed its owners with the gift of prophecy.
Yowah Nut is a variety of Boulder Opal that derives its name from a locality in the Australian Outback. The nodules are about walnut size and will have colorful veins running throughout.
- Characteristic Physical properties