When you think of expensive gemstones, what comes to mind? Most people think of the Big Four: diamonds, emeralds, rubies and ...

Gemstones have been a topic of fascination to human beings for centuries, not just for their beauty, but also for how rare ...

But this is true. The world’s most expensive stone is not diamond but the rarest mineral is kyavathuite and painite. According to information, minerals are found almost everywhere on earth.

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 ...

High-quality black opal can cost over $10,000 per carat, 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.

‘Expensive’, ‘touristy’ Stonehenge ranked third most underwhelming tourist spot globally. (photo credit: Laurence Berger. Via Shutterstock) Stonehenge, the ancient stone circle in ...