5. Spinels

World’s Most Expensive Gem Stones

If you haven’t heard of spinel, you’re not alone. This gemstone is not one of the most famous, but it is still worth adding to your jewelry box. One of the best features of the spinel is that it can be found in a wide range of colors, including red, yellow, purple, blue, pink and orange. That covers just about every wardrobe ensemble imaginable. At their peak, these stones are valued at about $30,000 per carat.