A wheel loader operator fills a truck with ore at the MP Materials rare earth mine in Mountain Pass, California, U.S. January 30, 2020. REUTERS/Steve Marcus/File Photo Aug 2 (Reuters) - MP Materials (MP.N) and other Western companies are seeking to develop supplies of processed rare earths needed for the green energy revolution in a sector dominated by China. The 17 silvery-white rare earth minerals are not uncommon in the earth's crust. But deposits that are economically viable are more difficult to find, and the real rarity comes in the complex process to separate them into the materials needed to...