Tahitian Pearl Drop Necklace on 4mm Gold Vermeil Disc Chain with White Sapphire Bezel Set and Freshwater Pearl accents at the Lobster Clasp. Necklace is 16.5" and drop is 2.5". *We recommend accompanying this necklace with #458 which is an accenting choker. Evaluating the quality of a Tahitian Pearl - color, luster, size, surface quality andshape. Naturally large and round pearls have a higher value than small pearls with irregular shapes. With all other factor being equal, the larger the peal the more valuable it is. Round pearls are the most difficult to culture. The French Polynesian coral crowns in the middle of the great ocean continue to provide the perfect nutritious pristine environment necessary for Tahitian pearl cultivation.