• synonyms


  1. a mineral, a hydrous sulfate of potassium and aluminum, KAl3(SO4)2(OH)6, commonly occurring in fine-grained masses.
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Origin of alunite

1865–70; < French alun (< Latin alūmen alum1) + -ite1
Also called al·um·stone [al-uh m-stohn] /ˈæl əmˌstoʊn/.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for alunite

Historical Examples of alunite

  • Of other natural mineral sources, alunite is the most important.

    The Economic Aspect of Geology

    C. K. Leith

  • One of the interesting features of this occurrence is the abundance of alunite.

  • Alunite, al′un-īt, n. a mineral consisting of common alum together with normal hydrate of aluminium.

  • In the Goldfield camp (p. 230) the ores are closely associated with alunite in such a manner as to suggest a common origin.

  • Alunite is a potassium-aluminum sulphate, which differs from sericite in that sulphur takes the place of silicon.

British Dictionary definitions for alunite


  1. a white, grey, or reddish mineral consisting of hydrated aluminium sulphate. It occurs in volcanic igneous rocks and is a source of potassium and aluminium compounds. Formula: KAl 3 (SO 4) 2 (OH) 6
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Word Origin for alunite

C19: from French alun alum (from Latin alūmen) + -ite 1
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012