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
Pearl of Africa Rally its own African Rally Championship event in 1997. As Winston Churchill visited Uganda, he baptised the country as the ‘Pearl of Africa’, that's where this event receives its name from. Some remarkable drivers in the history of Uganda are Sospeter Munyegera, Shekhar Mehta, Satwant Singh, Charlie Lubega, Moses Lumala, Emmanuel Katto and Chipper Adams, amng others. Source: Motor Sport Uganda and African Rally Championship Pearl of Africa Rally Pearl of Africa Rally or Pearl of Africa Uganda Rally is one of the main motorsport events in Uganda. It is part of the National Rally Championship and the FIA African Rally