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

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

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

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