gold-tone 18K yellow gold brilliant-cut diamonds flush setting round pendant crab motif star 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. Hallmarked in the United Kingdom at the London Assay Office. 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.