This tourmaline is dark brown green and opaque in the central region, but suddenly becomes gemmy and yellow-green at the terminations. This sudden change is quite typical for Stak Nala tourmalines, although this example is a bit unusual in that it is doubly terminated.  The slanted termination appears perhaps to be a healed break. Minor albite variety cleavelandite also present. Small edge chips near the healed termination, otherwise very nice condition.