The crystals can grow stubby, but most often are elongated or pencil shaped. The most commonly seen tourmaline is the sodium-rich black variety known as schorl . It forms in simple to complex granitic pegmatites. Iron is the primary coloring agent in this material. If the pegmatite contained lithium, manganese, and other rare elements, the colored varieties of tourmaline known as elbaite could form.
Many elements can freely substitute for others in the tourmaline family.
Elbaites often form beautiful crystals in colors of pink, red, green, blue, orange, yellow, or other shades, even colorless. Authorities occasionally get into a dispute over what actual color tones comprise these varieties. For example, rubellite originally meant bright red, like a ruby. Eventually pink tones were referred as rubellite often enough that it became acceptable to some authorities and not to others. Often colors shade from one hue to another, sometimes blending, sometimes remaining distinct.