Mysticdrop 1.00 Ct Black Diamond Engagement and Plain Wedding (3mm comfort fit) Ring Set in Sterling Silver Timeless Engagement and Wedding Ring set in sterling silver. The Black diamond is A quality and the wedding band measures 3mm. Sterling Silver is 92.5% pure silver and 7.5% alloy. It is stronger than pure silver. 30 Day No questions asked Return Policy Free-Shipping within US Engagement and Wedding Ring set/April Birthstone