Here is a Tiffany & Co Platinum Diamond Solitaire Ring.  Made from Solid Platinum 950 and weighs 4.2 grams.  At the center you are looking at one Natural Round Brilliant Diamond that is 0.40Ct I Color VS1 Clarity Diamond.  The ring is a size 7.25, can be sized for FREE upon request ( please ask for sizing prior to purchase ).  Hallmarked Tiffany & Co , PT950, 16556025, 0.40CT.  The ring comes with Original Tiffany & Co Receipt, & Tiffany & Co Pouch.  Retail is $3,250 + Tax