Pearl with a mother of pearl bead center. In the cultured pearl industry, the resources used to create a mistaken all nacre baroque pearl is a drain on the production of round cultured pearls. Therefore, they are trying to improve culturing technique so that keshi pearls do not occur. All nacre pearls may one day be limited to natural found pearls. Today many "keshi" pearls are actually intentional, with post-harvest shells returned to the water to regenerate a pearl in the existing pearl sac. Tahitian pearls, frequently referred to as black pearls, are highly valued because of their rarity; the culturing
Pearl River (China) as the Pearl River just north of Guangzhou. The Pearl River is famed as the river that flows through Guangzhou. The Pearl River's estuary, Bocca Tigris, is regularly dredged so as to keep it open for ocean vessels. The mouth of the Pearl River forms a large bay in the southeast of the delta, the Pearl River Estuary, the Bocca Tigris separates Shiziyang in the north, Lingdingyang in the south, and Jiuzhouyang at the southern tip of the estuary surrounded by the Wanshan Archipelago. This bay separates Macau and Zhuhai from Hong Kong and Shenzhen. The Pearl River is so