A serious strand of Black Ice Diamonds, indeed! 16 inches and Forty-three carats of natural Black Ice Diamonds™ black diamonds gently taper from 3.3 to 3.7 millimeters. Step away from the Red Carpet, here you come! Worn by stars, models and even royalty, black diamonds are a must for every lady's fine jewelry collection. All Black Ice Diamonds™ black diamond necklaces are guaranteed to be only the finest natural, black, non-irradiated black diamonds.