gold-tone 18K yellow gold square and brilliant-cut black sapphires freshwater pearl embellishment floral design cross pendant lobster clasp fastening 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. Pearls should be the last thing that you put on in the morning and the first thing you take off at night. Avoid contact with perfumes or creams, and simply wipe with a soft cloth to clean.