Mikimoto 18ct White Gold 10mm Black A+ South Sea Pearl Necklace, PP 20296 B W. Over a century ago, Kokichi Mikimoto succeeded in creating the world\'s first cultured pearl. His quest for perfection and his love for these pure, lustrous gems of the sea were the guiding forces that built the house of Mikimoto. This classic Mikimoto necklace is a simple but stunning piece that features a single 10-11mm A+ grade Black South Sea cultured pearl set on an elegant 18ct white gold necklace, adjustable from 40 to 43cm. The necklace comes beautifully packaged in a unique Mikimoto presentation box with certificate of authenticity.