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
BlackBerry Pearl and in Canada through Rogers, Telus, and Bell Mobility. The phone has been known by many names, from the original codename BlackBerry "Kickstart" name to the current BlackBerry Pearl 8220 Smartphone name. A CDMA version is available for Verizon and Alltel known as the 8230. The Pearl Flip is very similar to the original Pearl and uses the same predictive text input that the Pearl uses. It has a 2.0-megapixel camera and video recording. It is the first BlackBerry to feature Wi-Fi and mobile calling in a new flip design. This 3G line came with 360 x 400, 2.25" TFT