Meet the "Virgin Rainbow" – perhaps the finest and certainly the most expensive opal on record. It literally glows in the dark. In fact, as it gets darker around the opal, the opal appears ever more ...

Following is a transcript of the video. Narrator: High-quality black opal can cost over $10,000 per carat, making it one of the world's most expensive gemstones. But mining black opal isn't easy.

JUNEAU, Alaska — A gemstone, billed as one of the largest gem-quality opals in existence, was sold for $143,750 at auction in Alaska on Sunday. The opal, dubbed the “Americus Australis,” weighs more ...