The tourmaline stone is unique because of its amazing variety of colours. As the crystal grows, it gradually changes colour. Another incredible fact about tourmaline is that depending on where it is from, the colour range changes within the crystal. Brazil produces crystals that grow from red to green on the outside rather like a watermelon, and Southern Africa produces crystals that grow from green to red on the outside. It is very unusual to find an entire crystal of tourmaline in only one colour. This is why it is very unusual and difficult to find a perfectly matching pair of tourmalines of any significant size. If there is a large piece of crystal, it would more often than not be cut into one large stone because it can be sold for much more per carat, as opposed to cutting it into a pair. This is the main reason that it is so difficult to match – bear that in mind if you have one and are trying to match it.