Tourmaline is a crystalline boron silicate mineral compounded with other elements to produce the differing tourmaline types. A variety of Tourmaline is Elbaite which is formed in a variety of rainbow coloured hues. Watermelon Tourmaline is one such type of elbaite that forms with beautiful green and reddish-pink colours.

These boro-silicates are typically formed when magma cools to form igneous rocks. As this happens, the boro silicates transform into the solid tourmaline from gas or liquid types. They are mainly found in granite pegmatites underwater.