We love spinels! They grow alongside rubies and sapphires in the mines and for centuries have been thought to be rubies and sapphires. They have many similar characteristics, but more sparkle. The most famous spinel is the Black Prince's Ruby in the Crown Jewels of England. In the early 1900s they tested the 'ruby' and discovered it was actually a spectacular red spinel. Spinels are hard enough for an every day ring making them excellent engagement rings.