allanite

noun Mineralogy.

1. a member of the epidote group, a silicate of calcium, cerium, aluminum, and iron, occurring chiefly in brown-to-black masses or prismatic crystals.

noun

1. a rare black or brown mineral consisting of the hydrated silicate of calcium, aluminium, iron, cerium, lanthanum, and other rare earth minerals. It occurs in granites and other igneous rocks. Formula: (Ca,Ce,La,Y) 2 (Al,Fe,Be,Mn,Mg) 3 (SiO 4) 3 (OH)