Previously-owned Tiffany & Co.Engagement Ring. The ring is a size 4 (US), made of platinum, and weighs 3.6 DWT (approx. 5.60 grams). It also has one G-color, VS1-clarity diamond weighing 1.37 CTTW, and ten D-G-color, FL-VS2-clarity diamonds weighing 0.33 CTTW.