A Japanese technician extracts a large, 15mm, South Sea pearl from an oyster on a pearl farm at Koh Sa Mae, Thailand, near the town of Pattaya. These large pearls are produced only by the giant oyster Pinctada maxima, which lives in tropical waters. Cultured pearls accrete around a 'seed', a sphere of freshwater mussel shell, and the surgery involved is delicate and skilled..