October’s birthstone (along with Opal), Tourmaline is a gem of many colors—and is sometimes colorless or even black. Long sought after as a jewel, the Dutch first began to import Tourmaline from Sri Lanka several centuries ago, calling it Turamali, meaning “stone with mixed colors.” In the Russian Crown Jewels collection, bright red Tourmaline masqueraded as Ruby until it was unmasked. Watermelon Tourmaline has a green “skin” and red “core,” and is sometimes sliced to accentuate this unique shift. Paraiba is a gorgeous blue-green Tourmaline that takes its hue from its copper component. All Tourmaline, regardless of its main hue, exhibits pleochrism, meaning that it shows depth of color and changes hue when viewed from different angles under different sources of light. Tourmaline can be cut in many different ways to emphasize this versatile play of hue, but is usually left untreated so its natural variation can shine through.