Matched 7mm round white Pearls: cultured, as is the vast majority of Pearls world-wide. Nowadays the only market for natural good-quality Pearl is Arabia, focused on natural Pearls from the Persian Gulf. Up to the commercialization of Cultured Pearl in the mid 1900s, Pearl was a  very costly gemstone, the plaything of only the rich and powerful since at least 2000bce, particularly in the empires of China and India and the near East. It is said that Pearl was at its most fabulously expensive at the time of the Roman Empire.
The above matched pair is a good modern example of fine cultured Pearl, being almost totally free of surface blemishes, and having fine lustre. Chinese origin; for quite some years now the production of Japan, where the cultured Pearl industry first properly blossomed, has been for its local consumption.