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 Qing Ding Pearl The Qing Ding Pearl The Qing Ding Pearl (《慶頂珠》, simplified 庆顶珠) is a Chinese play. It dates to the Song Dynasty and is still performed in adapted forms in the Beijing Opera. The play is known by other titles: Two sections (折 zhe) of the main play are sometimes performed separately as The Fisherman's Revenge《漁夫恨》 or A Fisherman Kills a Family (《打漁殺家》, simplified 打渔杀家 dayu sha jia) also Collecting the Fishing Tax (《討漁稅》 "taoyushui"). The play tells the story of Xiao En (whose real identity is Ruan Xiaoqi from "Water Margin"), a poor fisherman and his daughter who seeks bloody