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.

Black opals are rarely completely black ... making it one of the most expensive rings in the entire world. Pink diamonds are another form of fancy-color diamonds. Experts disagree about what ...

In 2000, jewelry company Le Vian capitalized ... making it one of the world's most expensive gemstones. Over 90% of black opals come from Australia, but they aren't easy to find.