Wielding a shiny chrome scoop, Michael Rosenthal leans over and digs into the powder in a half-filled 55-gallon drum. He holds up the scoop and takes a pinch in his fingers and smooshes it to show me the texture. It’s like talc, but it’s an odd, beautiful shade of pale green-gray. On shelves all around us are huge white bags of the stuff, each weighing a metric ton.

The fact that this particular powder exists at all is basically a miracle. That’s the inescapable conclusion for me at this point after a sort of impromptu, peripatetic mini-seminar conducted by Rosenthal here in Mountain Pass, Calif., near the Nevada border. Rosenthal is cofounder and chief operating officer of MP Materials, the only company in North America that is mining rare earth ore and—this is the important part—extracting from it large quantities of industrially useful rare earth compounds.