Description This Natural London Blue Topaz Gemstone, Displays a beautiful medium dark grayish blue color, with an excellent cut, symmetry and polish with a clarity grading of "Eye Clean Plus". Blue Topaz gemstone has been enhanced using a standard radiation treatment that is in full compliance with the USNRC standards. NOTE: Be sure to select the RIGHT gemstone/diamond by millimeter size only. Selecting your gemstone/diamond by carat weight is NOT ACCURATE. The best way to select the right size gemstone/diamond is to use our size chart image or consult with a local jeweler to measure your setting or gemstone. Dimensions: 2.00 x 10.00 mm Carats: 6.6 Shape: Antique Cushion Clarity: Eye Clean Make: Very Good Symmetry: Very Good Treatment: Enhanced Identification: Dealer