alunite

[al-yuh-nahyt]

noun

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/.

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.
The Economic Aspect of Geology
C. K. Leith
Alunite, al′un-īt, n. a mineral consisting of common alum together with normal hydrate of aluminium.
Chambers's Twentieth Century Dictionary (part 1 of 4: A-D)
Various
In the Goldfield camp (p. 230) the ores are closely associated with alunite in such a manner as to suggest a common origin.
The Economic Aspect of Geology
C. K. Leith
Alunite is a potassium-aluminum sulphate, which differs from sericite in that sulphur takes the place of silicon.
The Economic Aspect of Geology
C. K. Leith

British Dictionary definitions for alunite

alunite

noun

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