18kt yellow gold polished finish delicate chain heart pendant pavé-set round-cut diamonds totalling 0.05 carats lobster claw fastening Hallmarked in the United Kingdom at the London Assay Office. 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.