Tourmaline with a red center, surrounded by a green layer (or vice versa) – a bi-color - is popularly called Watermelon Tourmaline.
They are usually cut to display the two color-zones within the same gem. The name Tourmaline comes from the Singhalese (Sri Lankan) words 'tura mali ' –Gem with several colors. There are tourmalines in a variety of colors, some have two or more colours, some even color-changing.
