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
Hymn of the Pearl has been preserved and especially treasured in Manichaeism - a version of it appears as part of a north-African Manichaean Psalm book is written in Coptic, called the Psalms of Thomas. The Hymn of the Pearl has also been admired by Orthodox Christian thinkers and members of the Church of Jesus Christ of Latter-Day Saints (Mormons). Please note that wikisource contains the . The "Hymn of the Pearl" is read as part of the narration in Terrence Malick's 2015 film "Knight of Cups". The film deals with themes of pain, loss of direction and transcendence, which are part of the