silver-tone 18K white gold yellow diamond emerald-cut yellow diamond round brilliant cut white diamonds halo setting double halo design Normal everyday use and external agents may reduce the lustre of gemstones and gold surfaces. To maintain, use specific, non-abrasive products specially meant for cleaning jewellery. Includes a GIA report. This certification from the Gemological Institute of America assesses diamonds' authenticity as well as cut, colour, clarity and carat weight.