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 ...

30 Most Expensive Green Gemstones, Ranked by Price ... yes, emeralds tend to be the most popular green gemstone, they’re certainly not the only one and not even the most expensive by carat weight.

Gemstones have been a topic of fascination ... The red diamond tops the list as the most expensive Diamond in the world that is, valued at a whopping price of up to $1 million per carat.

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.