MP Materials, which runs the only American rare earths mine, announced a new $500 million agreement with tech giant Apple on Tuesday to produce more of the powerful magnets used in iPhones as well as other high-tech products like electric vehicles.

The factory will develop a series of neodymium magnet manufacturing lines specifically designed for Apple products.

The iPhone maker is committing $500 million to buying rare-earth magnets from the company’s flagship facility in Texas, which Apple is helping to build out.