China’s exports of gallium and germanium, essential minerals for semiconductor manufacturing, fell to zero in August after Beijing imposed curbs on sales overseas due to national security concerns. China produces 80% of the world’s gallium and 60% of germanium, but did not sell any of the elements on international markets last month. In July, the country exported 5.15 metric tons of forged gallium products and 8.1 metric tons of forged germanium products. China’s commerce ministry has received applications from companies to export the two materials, with some approved. The curbs are seen as a retaliation against US export controls, despite concerns about economic growth and a tech war. The world’s second largest economy is already struggling with weak domestic demand and a housing crisis.