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

Origin of alunite

1865–70; < French alun (< Latin alūmen alum1) + -ite1
Also called al·um·stone [al-uh m-stohn] /ˈæl əmˌstoʊn/. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for alunite

Historical Examples of alunite

British Dictionary definitions for alunite



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

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