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 ...

Spiny Oyster Shell is considered rare because it is only found in a limited geographic area and is only available in certain seasons. The Spiny Oyster itself is found in warm waters off the coasts ...

This 1997 Shaquille O'Neal Metal Universe Precious Metal Gems in a PSA 4 sold for a record $20,400 in Alt Auctions. This is the record all-time for a PSA 4 copy. While Panini often releases rare ...

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 ...