Mumbai is the capital of the Indian state of Maharashtra and the financial capital of India. With an estimated population of thirteen million, it is the most populous city in India and the most populous city in the world Along with the neighbouring suburbs of Navi Mumbai and Thane, it forms, at nineteen million, the world's fifth most populous metropolitan area. Mumbai lies on the west coast of India and has a deep natural harbour. Mumbai's port handles over half of India's maritime cargo. Mumbai was known as Bombay. Mumbai is the commercial and entertainment centre of India, generating 5% of India's GDP and accounting for 25% of industrial output, 40% of maritime trade, and 70% of capital transactions to India's economy. Mumbai is one of the world's top ten centres of commerce by global financial flow, home to such important financial institutions as the Reserve Bank of India, the Bombay Stock Exchange, the National Stock Exchange of India and the corporate headquarters of many Indian companies and numerous multinational corporations. The city also houses India's Hindi film and television industry, known as Bollywood. Mumbai's business opportunities, as well as its high standard of living, attract migrants from all over India and, in turn, make the city a potpourri of many communities and cultures.

Pearls

The finest quality natural pearls have been highly valued as gemstones and objects of beauty for many centuries, and because of this, the word pearl became a metaphor for something very rare, very fine, very admirable and very valuable. A pearl is a hard, round object produced within the soft tissue of a living shelled mollusk. Just like the shell of mollusks, a pearl is composed of calcium carbonate in minute crystalline form, which been deposited in concentric layers. The ideal pearl is perfectly round and smooth, but many other shapes of pearls occur. Almost any shelled mollusk can, by natural processes, produce some kind of pearl when an irritating microscopic object becomes trapped within the mollusk's mantle folds, but virtually none of these pearls are valued as gemstones. A black pearl and a shell of the black-lipped pearl oyster are interesting. Two groups of mollusk can bivalves or clams produce saltwater pearl oyster farm, Serum, Indonesia Nacreous pearls, and the most desirable pearls. One family lives in the sea: the pearl oysters. The other, very different group of bivalves live in freshwater, and these are the river mussels. Saltwater pearls can grow in several species of marine pearl oysters in the family Pteriidae. Freshwater pearls grow within certain) species of freshwater mussels in the order Uniondale, the families Uniondale and Margaritiferidae. These various species of bivalves are able to make nacreous pearls because they have a thick iridescent inner shell layer called mother of pearl, which is composed of nacre. The mantle tissue of a living bivalve can create a pearl in the same manner that it creates the pearly inner layer of the shell.