Original link: China has stopped exporting rare earths to everyone, not just the U.S., cutting off critical materials for tech, autos, aerospace, and defense / Fortune / Yahoo.
Not surprising given raising tension including but not limited to raging trade war.
Rare earths are 17 elements - Wikipedia..
Replacement production in Sourth Africa, Australia and the US are expected to start up. Vietnam and Brazil also got huge reserves. When China exported (some say at dumping prices) then that was not financially feasible, but with an export stop and raising prices then it becomes financially feasible.