Tourmaline presents itself in a rainbow of colors, making it one of the most colorful, and most popular, gemstones. Tourmaline crystals form by hydrothermal activity in igneous and metamorphic rocks. The crystals form when hot water and vapors carry the necessary elements to form tourmaline in the empty spaces of rock- pockets, voids, and fractures. Brazil has been the world’s leading source of Tourmaline for nearly 500 years. Portuguese in the 1500s thought the colorful stones they obtained from indigenous people and streams were emeralds and sapphires- Tourmaline was not recognized as a distinct mineral until 1793.