Tourmaline

Tourmaline is found in a variety of colors. Iron-rich tourmalines are black to bluish black to deep brown. Magnesium-rich varieties are brown to yellow, and lithium-rich tourmalines are almost any color; blue, green, red, yellow, pink, etc. Bi-colored and multicolored crystals are common. They are usually green at one end and pink at the other. Watermelon tourmalines are green on the outside and pink inside.   Tourmalines are 7-7.5 on the Mohs scale.