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
Daniel Pearl On December 10, 2007, President George W. Bush and Laura Bush invited Ruth and Judea Pearl, parents of Daniel Pearl, to the White House Chanukah reception. They lighted the Pearl family menorah that once belonged to Daniel's great-grandparents, Chaim and Rosa Pearl, who brought it with them when they moved from Poland to Israel in 1924. There they helped establish the town of Bnai-Brak. The late former mayor of New York City Ed Koch requested that his own tombstone be inscribed with Pearl's words: "My father is Jewish, my mother is Jewish, I am Jewish." Shortly after Pearl's death, his