While pearls are considered gemstones, they are not minerals but ... which accounts for both its name and its rarity. The supply of Tanzanite will likely be finished in the next 20 years.

The recent Knight Frank Luxury Investment Index highlights the growing appeal of precious stones, diamonds and coloured ...

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 ...