The world’s largest known rare earth deposit in northern China could contain far more resources underground than currently reported, according to a leading Chinese geologist. Containing 100 million tonnes of rare earth reserves, the Bayan Obo mine in the Inner Mongolia autonomous region has served as the backbone of China’s rare earth industry for decades. According to Yang Li, a Peking University geologist, “Bayan Obo’s rare earth resources have been the dominant source of global rare earth...