Spinels are often called the great imposters of the gem world for their cunning ability to masquerade as rubies and sapphires. First discovered in Badakhshan, a province in Northern Afghanistan, spinel forms in a range of colors, from ruby-like crimson to fiery orange, vivid green, sapphire blue, and violet. The British Crown Jewels contain perhaps the most famous example of the stone’s mistaken identity: the crown’s 170-carat central gem, confusingly called the Black Prince’s Ruby. Though still beautiful, the spinel makes the piece far less valuable than if it were a ruby. Here, Robb Report highlights four contemporary designs that celebrate the true splendor of this vexing gem.