Jean Charles Galissard de Marignac
Jean Charles Galissard de Marignac was a Swiss chemist whose work with atomic weights suggested the possibility of isotopes and the packing fraction of nuclei. His study of the rare earth elements led to his discovery of ytterbium in 1878 and co-discovery of gadolinium in 1880.
Jean Charles Galissard de Marignac
The family grave
The rare-earth elements (REE), also called the rare-earth metals or rare earths or, in context, rare-earth oxides, and sometimes the lanthanides, are a set of 17 nearly indistinguishable lustrous silvery-white soft heavy metals. Compounds containing rare earths have diverse applications in electrical and electronic components, lasers, glass, magnetic materials, and industrial processes.
Rare-earth ore (shown with a 19 mm diameter US 1 cent coin for size comparison)
Refined rare-earth oxides are heavy, gritty powders usually brown or black, but can be lighter colors as shown here.Legend: gadolinium · praseodymium · cerium samarium · lanthanum neodymium
False-color satellite image of the Bayan Obo Mining District, 2006