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
The Thirteenth Pearl The Thirteenth Pearl The Thirteenth Pearl is the fifty-sixth volume in the Nancy Drew Mystery Stories series. It was first published in 1979 under the pseudonym Carolyn Keene. The actual author was ghostwriter Harriet Stratemeyer Adams. "The Thirteenth Pearl" is the end of the original 56-book series published by Grosset & Dunlap. Subsequent volumes were published by Simon & Schuster. Nancy Drew is asked to locate a missing pearl that is unusual, but very valuable. She soon learns that dangerous people are responsible for the theft. They begin harassing her at home and it intensifies when Nancy and her father