Tiffany & Co. Platinum 4.18 ct Total Weight Emerald Brilliant Cut Diamond Engagement Ring. The ring weighs 5.2 grams, size 6 the center stone is a Natural Emerald Cut diamond weighing 4.02ct, F in Color, VVS1 in Clarity, Excellent Cut, Very Good Polish, & Excellent Symmetry, with Faint Fluorescence. The Center diamond has a Tiffany laser crown inscription on the crown GIA on the Girdle.