18kt yellow gold 18kt yellow gold Double Pearl ring from DELFINA DELETTREZ featuring 18kt yellow gold, polished finish, bezel setting and freshwater pearl. Hallmarked in the United Kingdom at the London Assay Office.. 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..