METALS: The Rare Earths

No commercial metals are so scarce as a group of 15 known as the "rare earths." They are so rare, in fact, that there is some question as to whether one of them exists at all. They have tongue-twisting names (praseodymium, gadolinium, cerium, lanthanum, ytterbium, etc.), are found in rare mineral deposits, mostly in India and Brazil. Until recently, the metals had limited uses.

In the jet and atom age, these rare-earth metals have suddenly come into new importance, have sent companies scrambling for new sources. Cerium, for example, combines with magnesium and aluminum to make tough, light, heat-resistant alloys ideal for jet-engine parts. The Atomic Energy Commission is interested in cerium's cousins because they are useful in shields against atomic radiation, have other secret uses.

Last week Molybdenum Corp. of America, which specializes in producing alloys used for hardening steel, had some big news about the rare-earth metals. A deposit discovered a year ago by the company near the Nevada-California line, said President Marx Hirsch, "is a major metal discovery." He estimated that there are 14 of the 15 rare metals in the ⅓ sq. mi. deposit.

On the basis of Hirsch's announcement, Moly Corp. stock, which has scooted from 7½ to 64½ in two years, scooted up another 15¼ points to 79¼. If the deposit lives up to Hirsch's hopes, the U.S. will no longer have to rely on imports of the earth's once forgotten elements.