Lithos Natural Emerald & Cultured Freshwater Coin Pearl Interchangeable Clasp Necklace. The coin pearls are 21.0 mm. There are seed pearls in between the emeralds and button pearls. The pearls are natural color, freshwater, cultured Chinese pearls. The largest emerald bead is 14.5 mm by 9.56 mm. The rest average from 7.0 mm to 9.0 mm. The ends are 18K yellow gold and it is strung on stainless steel wire. This necklace is 19 inches long. The interchangeable clasp system is also called the Vario, Gellner and Jorg Heinz system. The interchangeable clasp is not included. 500-30-689