15 carats of natural black diamonds! This deliciously glittering black diamond necklace is all about the subtle appeal of understated elegance. 16 inches and Twelve carats of natural Black Ice Diamonds™ black diamonds gently taper from 1.7 to 2.2 millimeters. Fastened with a solid white gold clasp, this is a must for today's fashionable ladies. All Black Ice Diamonds™ black diamond necklaces are guaranteed to be only the finest natural, black, non-irradiated black diamonds.