Cultured pearl is calcium carbonate and a fibrous protein called conchiolin. As the nacre builds up in layers of minute aragonite tablets, it fills the growing pearl sac and eventually forms a pearl. Natural pearls are formed by nature, more or less by chance. On the other hand, cultured pearls are human creations formed by inserting a tissue graft from a donor oyster, upon which a pearl sac forms, and the inner side precipitates calcium carbonate, in the form of nacre or "mother-of-pearl". The most popular and effective method for creating cultured pearls are made from the shells of freshwater river mussels
The Pearl of Death The Pearl of Death The Pearl of Death is a 1944 Sherlock Holmes film starring Basil Rathbone as Holmes and Nigel Bruce as Dr. Watson, the ninth of fourteen such films the pair made. The story is loosely based on Conan Doyle's short story "The Adventure of the Six Napoleons" but features some additions, such as Evelyn Ankers as an accomplice of the villain, played by Miles Mander, and Rondo Hatton as a brutal killer. Master criminal Giles Conover (Miles Mander) steals the famous "Borgia Pearl" from the Royal Regent Museum under the very nose of Holmes and Watson, but