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-Qatar project was first revealed, the initial cost of constructing the island stood at $2.5 billion. It is now believed the project will cost $15 billion upon completion. The name "The Pearl" was chosen because the island is being built on one of Qatar's previous major pearl diving sites. Qatar was one of the major pearl traders of Asia before the Japanese introduced cheaper more affordable pearls just before Qatar's oil boom. The Pearl Qatar will help represent Qatar's rich past in the pearl industry. Once completed The Pearl will resemble a string of pearls. Residential development on the island is