Molycorp said Mark Smith's departure from the company, which mines minerals that are crucial ingredients for mobile phones, was unrelated to a regulatory investigation into the company's public disclosures.
It was once an obscure topic only for geologists. But China's control over rare earth elements used in green- and high-tech equipment is causing alarm as the nation cuts exports.
The most recent trove of images sent back by NASA's Cassini spacecraft offers stunning new shots of Saturn and its rings.
Molycorp, which plans to officially reopen its rare-earth mine in California this week, buys a company which can manufacture neodymium-based alloys for permanent magnets from the minerals it mines.
The planned joint venture would bring manufacturing of rare earth alloys and magnets to the U.S.
Republic reduces its first batch of rare earth export quotas for 2011 by more than 11 percent, in the face of a threat by the U.S. to complain to the WTO over the limits.
Nations are pressing for solutions to concerns China may be exploiting stranglehold on metals crucial in the making of portable phones, wind turbines.
But China says it regrets the WTO's decision, a ruling that could have implications for the legality of the country's rare-earth export quotas. China insists its policies are based on environmental and resource protection.
Did you ever wonder how your iPhone screen got its color? It's from rare-earth minerals. CNET's Jay Greene takes you on a tour of a rare-earth mineral mine in California, where you'll see firsthand how rocks become the pixie dust that powers your iPhone.
The country, which holds a third of the world's reserves of specialty metals, eats up to 60 percent of global supply for use in consumer gadgets, medical equipment, and hybrid cars.