Presenting you a Beautiful watermelon tourmaline crystal from Nigeria Tourmaline is a diverse group of boron silicate minerals celebrated for having one of the broadest color ranges of any gemstone. Known as the "rainbow crystal," it occurs in virtually every shade, including unique multicolored varieties like watermelon tourmaline. Tourmaline is unique for its pyroelectric and piezoelectric properties, meaning it can generate an electrical charge when heated or placed under pressure. Weight: 21 grams