18kt yellow gold and sterling silver Châtelaine blue topaz and diamond stud earrings from DAVID YURMAN featuring 18kt yellow gold, sterling silver, topaz, pavé-set diamonds and post-back fastening. These earrings come as a pair.. 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..