These are cultured mostly in the lakes and rivers of China using Hyriopsis cumingi as the host oyster. The pearls are usually either shaped like grains of rice or are oval-shaped. Semi-spherical pearls are grown mainly in the so-called 'mabe' oysters and are therefore commonly referred to as 'mabe pearls.' They adhere to the inner wall of the oyster and thus take on semi-spherical shape.
