18kt yellow gold polished finish cabochon-cut turquoise bezel-set princess-cut iolite bezel-set trillion-cut blue topaz twisted detailing open band 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. To ensure the shine and polish of your David Yurman piece, wash with a little non-bleach, soapy water and wipe clean with a soft cloth.