Due to its wide array of vivid colors and the fact that is was usually mistaken as a different gem, there is very little history on tourmaline. Tourmaline is a mixture of boron, silicon, and aluminum, with the addition of another element that defines its color. For example, iron is present in green and blue tourmaline while manganese is present in the pink and red tourmaline.
Some of the more popular colors have earned special names in the gem trade. The green tourmaline is called chrome tourmaline when its green is intense enough to resemble that of an emerald. Watermelon tourmaline is a mix of pink and green. A very valuable form is the ruby red variety, this tourmaline is referred to as rubellite. Varieties of tourmaline can be mined on every continent.