Tourmaline is the most colorful of all gemstones because, according to an ancient Egyptian legend, it passed through a rainbow on its journey to Earth and brought all of the colors of the rainbow with it.

Tourmaline crystals are more likely to have two (or more) colors than just one, or at least two or more tones of one color. Even minor changes in a tourmaline's chemical composition can serendipitously result in entirely different colors within the single crystal.