Elbaite variety Tourmaline.  This is an extremely large crystal of Tourmaline that exhibits a rainbow-like coloration.  Extremely sharp luster and classic Tourmaline crystal shape make this a fine example of the species.  A famous find of rainbow Tourmalines keep miners digging at the Sapo Mine hoping to find pieces that rival the aforementioned crystals.  A flat termination at the crown of this crystal, superior luster and significant bi-color change makes this piece a perfect example of tourmaline from this locality.