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 (novel) the end, the finding of the great prize causes him to lose another, his son. Perseverance -The theme of perseverance is demonstrated by many characters, but mainly Kino. Before he found the pearl, he was a noble and a very determined person who sought fortune for his family. After he finds it, he is hoping to find it in a diffrent way. Because Kino believes that this would save his family, he persists “though many obstacles”that accompany the pearl. He perseveres to keep the pearl but, in the end, it was not worth keeping. Kino is the main character that