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. After investing tens of thousands of ...

Opals are formed when water and silicon dioxide leak into natural faults in the earth or fossils, forming a gem with sparkling colors. Black opals are rarely completely black, usually dark gray ...

The shinier the pearl, the better. Black opal is one of the rarest gemstones in the world, sought after for its seemingly infinite display of colors, compared to common opal, which is usually one ...

COUNTRY Championship Final winning trainer Gary Colvin is eyeing off a tilt at the time-honoured Black Opal Stakes should his ...