When you think of expensive gemstones, what comes to mind? Most people think of the Big Four: diamonds, emeralds, rubies and sapphires. However, it might surprise you to know that there are ...

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 ...

A rare square 37-carat emerald owned by the Aga Khan fetched nearly $9 million at auction in Geneva on Tuesday, making it the world's most expensive green stone. Sold by Christie's, the Cartier ...

A single curling stone certified for the Olympics costs over $600. That makes a full set of 16 stones worth $9,600. Since 2006, every stone used in the Olympic Winter Games has come from Kays of ...

Scientists said recently they have found the “missing ingredient” for pink diamonds, some of the world’s most expensive stones due their rarity and beauty, and the discovery could help find ...