Collection: All Opals

There are two broad classifications of opal: precious, which displays iridescence, and common, which does not. Iridescence is a colorful effect resulting in flashes of colored light from certain minerals as they are turned in white light. Depending on the formation conditions, opal may be transparent, translucent, or opaque. White, gray, and green opals are among the most common, whereas black opal is considered the rarest.