Mosandrite is a rare-earth element (REE)-bearing silicate with the formula [([??], Ca, Na).sub.3] [(Ca, REE).sub.4] Ti [([Si.sub.2][O.sub.7]).sub.2][[[H.sub.2]O, OH,F].sub.4] * [H.sub.2]O, where [??] = a vacancy (Sokolova and Hawthorne, 2013).
A 0.38 ct faceted mosandrite (Figure 7) of brown-orange colour was investigated by standard gemmological methods.
But it was not until 1839 that, after much pushing by Berzelius, he published the discovery of the new element lanthanum (La)--from the Greek word lantanein, "being hidden." In the same year the Swedish mineralogist and geologist Axel Erdmann (1814-1869) also discovered lanthanum, in a Norwegian mineral which he named mosandrite
in honor of Mosander's discovery (Lundgren, 1987).
Dr Ulrich Henn (German Gemmological Association, Idar-Oberstein) reported the properties of some rare gem materials: wurtzite from Merelani, Tanzania; mosandrite
from the Kola Peninsula, Russia (see Gem Note on pp.
The current view (Fleischer and Mandarino, 1995) is that rinkite is a valid species, and mosandrite is an altered variety of rinkite.
(1989) Nacareniobsite-(Ce), a new mineral species from the Ilimaussaq alkaline complex, South Greenland, and its relation to mosandrite and the rinkite series.