Tourmaline: S have a very

Tourmalines have a very complex chemical composition, and more than a dozen mineral species are recognized within this group. Their highly variable chemical composition gives rise to a wide range of colors. Among the many varieties of elbaite tourmaline are verdelite (green), indicolite (blue) and ... Learn about the 15 different types of tourmaline, a group of minerals with stunning colors and electric properties. Discover where to find them in various geological settings around the world. Tourmaline TrigonalXY3Z6Si6O18(BO3)3(O,OH)3(O,OH,F)The tourmaline group is a family of boron-bearing aluminium cyclosilicates that contain alkali elements (Na, Ca and even Li), Fe, and Mg. Notable members of the tourmaline group include elbaite, schorl, and dravite, which are common accessories Learn about tourmaline, a fascinating gemstone with a wide range of colors and unique properties. Discover its composition, crystal structure, formation, occurrence, types, history, uses, and more.