Genuine Boulder Opal: Formed by a combination of silicon dioxide and water trapped within solid rocks like limonite, sandstone, rhyolite, marl, and basalt, opal is distinguished by its iridescent play of color—a.k.a. “fire”—which reveals itself when exposed to a light source. It’s also the birthstone for October.
Several varieties are used in jewelry, including:
-Boulder Opal found in cracks or coatings in and around ironstone and sandstone boulders.
-Doublet Opal which is a thin slice of precious opal cemented onto a backing, usually a piece of ironstone.
-White Opal which has a milky pale white appearance with bright flashes of fire
Metaphysical Properties: A common misconception is that it’s bad luck to wear opals if they’re not your birthstone. The fact is that opal was a good luck talisman in ancient times and today is regarded as a symbol of hope, innocence and purity. It’s a healing, protective stone that also intensifies emotions and releases inhibitions.
Origin: Australia, Ethiopia, Peru, U.S