MP Materials announced a $500 million partnership to supply Apple with rare-earth materials from its US mine, sending shares soaring.

The deal, announced on Tuesday, guarantees Apple a steady flow of rare earths and magnets free from China, the world's largest producer.

Rare-earth miner MP MaterialsMP soared during stock market trade on Thursday after announcing a multibillion dollar public-private partnership with the U.S. Department of Defense to "dramatically accelerate the build-out of an end-to-end U.