Watermelon tourmaline is an interesting multi-colored elbaite variety.
Cat's Eye Tourmaline
The term cat's eye, or chatoyancy, is used to describe a phenomenal optical property in gemstones, in this case tourmaline.
The tourmaline family consists of at least 14 distinct minerals, but the variety elbaite accounts for nearly all gem-quality tourmaline.
When Paraiba tourmaline was first discovered in Brazil in the 1980's, the unusually intense "neon" or "electric" blues and greens set it apart from any other tourmaline previously known.