Although cultured pearls are genuine pearls, they grow due to human intervention. Natural pearls, on the other hand, grow without any human intervention. The growth process for both types of pearls, however, is the same. The pearls grow when an irritant works its way into an oyster shell either naturally or with human assistance. The irritant (usually a bead for cultured pearls) causes layers of nacre to form around it, which creates the pearl. Natural pearls are rare and consequently quite expensive. Cultured pearls are not rare, and therefore, while beautiful, far less costly.
