Investor interest in rare-earth minerals is rising, a source of strength for shares in the rare-earth miner MP Materials. The stock rose Friday after jumping late Thursday following a Bloomberg report that the Defense Department might provide additional capital to boost production.

The tentative deal between the United States and China may represent a retreat from the worst-case scenario of a total collapse of trade between the world's two biggest economies, but it creates more problems than it solves.

The U.S. trade "deal" with China highlights how dependent Americans are on Chinese rare earth minerals, creating an economic vulnerability.