MP Materials Corp., the operator of the only U.S. rare-earth mine and processing complex, said it has begun marketing a $500 million public offering of common stock. All shares will be sold by the company. The Las Vegas-based miner plans to channel the proceeds into accelerating and enlarging its operations, including construction of the so-called 10X Facility designed to increase domestic magnet output. J.P. Morgan Securities and Goldman Sachs are acting as lead book-running managers, and deal terms being circulated to investors indicate a price range of $54.50 to $56.00 a share. MP Materials’ stock has surged about 255% this year, buoyed by a $150 million Pentagon loan and a $500 million magnet-supply agreement with Apple that underscore Washington’s push to reduce reliance on Chinese rare-earth supply chains. The new equity raise is intended to give the company additional capital as it scales production to meet demand from defense and technology customers.