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The rare-earth elements (REE), also called the rare-earth metals or rare earths, and sometimes the lanthanides or lanthanoids (although scandium and yttrium, which do not belong to this series, are usually included as rare earths), [1] are a set of 17 nearly indistinguishable lustrous silvery-white soft heavy metals. Compounds containing rare ...
Rare-earth ore, shown with a United States penny for size comparison. A rare-earth mineral contains one or more rare-earth elements as major metal constituents. Rare-earth minerals are usually found in association with alkaline to peralkaline igneous complexes in pegmatites. This would be associated with alkaline magmas or with carbonatite ...
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The two are both rare-earth fluorocarbonates, but parisite's formula of Ca(Ce, La, Nd) 2 (CO 3) 3 F 2 contains calcium (and a small amount of neodymium) and a different ratio of constituent ions. Parisite could be viewed as a formula unit of calcite (CaCO 3 ) added to two formula units of bastnäsite.
Villiaumitic lujavrite, Kvanefjeld. Field of view is 1.75 cm wide. Click for link to additional photos. Kvanefjeld (or Kuannersuit), in Greenland, is the site of a mineral deposit, which is claimed to be the world's second-largest deposit of rare-earth oxides, and the sixth-largest deposit of uranium.
English: These rare-earth oxides are used as tracers to determine which parts of a watershed are eroding. Clockwise from top center: praseodymium, cerium, lanthanum, neodymium, samarium, and gadolinium.
See: Rare earth industry in China.) Although current evidence suggests rare-earth elements are less abundant on the Moon than on Earth, [60] NASA views the mining of rare-earth minerals as a viable lunar resource [61] because they exhibit a wide range of industrially important optical, electrical, magnetic and catalytic properties. [1]
It is a rare-earth element and the eleventh member of the lanthanide series. It is a relatively soft, silvery, fairly corrosion -resistant and malleable metal. Like many other lanthanides, holmium is too reactive to be found in native form, as pure holmium slowly forms a yellowish oxide coating when exposed to air.