Samarskite a. : A rare mineral having a velvet-black color and submetallic luster. It is a niobate of uranium, iron, and the yttrium and cerium metals.

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Taxonomy
MINERAL SAMARSKITE, free encyclopedia, specimen, minerals, m 2, yellowish brown, masses, dipyramidal, REE, Fe3, orthorhombic, brittle fracture, search, Uniformly, crystals, bcn, Imperfect, conchoidal.

Defination from the web:
Samarskite was first described in 1847 for an occurrence in Miass, Ilmen Mountains, Southern Ural Mountains of Russia. The chemical element samarium was first isolated from a specimen of samarskite in 1879. ... Retrieved from "http://en.wikipedia.org/wiki/Samarskite" ...