43 Carat Black Ice Diamonds Black Diamond Necklace BI-43-WA 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.