Tiffany & Co Lucida Diamond Ring. It is not graded as a loose diamond. So please consider the grade as a reference only. The girdle of the diamond is laser engraved with LUCIDA (visible only under a microscope). (Visible only under a microscope). The faceted portion of the diamond is laser engraved with T & Co. And the serial number. (Visible only under a microscope). Beautifully designed diamond ring! Ring Diamond 0.77 ct. Material: Platinum 950 Weight: 4.3g Size: US: 4.5 International: No. 9 (9 JP / US 5) Resizing: possible up to size 8 (8 JP / US 4)-11.5 No resizing fee (Resizing takes 3-5 days.) Condition Polished Accessories: • Ring size listed will usually be international sizing. Unless otherwise stated. Please use the Ring Size Chart for conversion.