About the brand: Timeless beauty and superior craftsmanship - a jewelry icon. This is an authentic, pre-loved Tiffany & Co. piece. It's possible that there may be some gentle wear. Platinum Princess-cut Prong-set Diamond = approximately 0.75 ct. tw. Ring can be re-sized by any professional jeweler; however, if re-sized, it will not be accepted for return It is customary to treat most gemstones to achieve enhanced color and durability. Some of these treatments may not be permanent, and may require special care. Please note: In product titles ct. tw. refers to the total carat weight of all diamonds and/or gemstones combined.