allanite

American  

[al-uh-nahyt] / ˈæl əˌnaɪt /

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.

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allanite British  

/ ˈæləˌnaɪt /

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)

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Other Word Forms

• allanitic adjective

Etymology

Origin of allanite

1835–45; named after Thomas Allan (1777–1833), English mineralogist; -ite ¹

Example Sentences

“That’ll be the allanite. It’s a rare earth mineral,” Wilson explains.

From The Guardian

Belonging to the same isomorphous group with epidote are the species piedmontite and allanite, which may be described as manganese and cerium epidotes respectively.

From Project Gutenberg

Although not a common mineral, allanite is of fairly wide distribution as a primary accessory constituent of many crystalline rocks, e.g. gneiss, granite, syenite, rhyolite, andesite, &c.

From Project Gutenberg

Allanite is a mineral readily altered by hydration, becoming optically isotropic and amorphous: for this reason several varieties have been distinguished, and many different names applied.

From Project Gutenberg