The U.S. Geological Survey has significantly revised down its estimate of Vietnam’s rare earth reserves to 3.5 million metric tons from 22 million tons, a change that if verified could affect the country’s ambitions to be a rare earths powerhouse. Rare earths are used in multiple industries, including electric vehicles, auto batteries and renewables, and have applications in electronic and military products. The revision, published in a January report, has moved Vietnam from second position on the USGS’s list of countries with the largest reserves down to 6th, after China, Brazil, India, Australia and Russia. “The rare earth reserve updates...