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KAl3(SO4)2(OH)6 A mineral composed of a basic potassium aluminum sulfate; it occurs as a hydrothermal-alteration product in feldspathic igneous rocks and is used in the manufacture of alum. Also known as alumite; alum rock; alumstone.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



a mineral of the complex sulfate group, with extra (OH)- anions. The chemical composition KA13[SO4]2(OH)6 sometimes includes admixtures of Na+ and Fe3+. Alunite crystallizes very rarely in a trigonal system. The mineral is mostly found in the form of fine-grained or friable earthy, sometimes fibrous, aggregates. The color is white, with grayish, yellowish, and reddish tints. The hardness of alunite on the mineralogical scale is 3.7–4.5; its density is 2,600–2,800 kg/m3. Alunite is formed by reworking acid and neutral volcanic rocks that contain orthoclase with hydrothermal sulfuric acid solutions and also by the action of sulfate surface water on aluminiferous rocks. Rocks containing alunite are a source of alum, alumina, potassium salts, and other substances.


The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
For the sulfur fertilisers, plant yield relative to the control increased slightly for jarosite and alunite and more than trebled for gypsum for the 240 mg S/pot application (Fig.
Other associated minerals are: nitratine, montmorillonite, paratacamite, atacamite, gunningite, alunite and natrojarosite.
The Rahy colt looks the sort to have on your side in a scrap, and he picked up well and sped on in good style from Alunite and Slip Stream.
In laboratory leaching studies he reported the following sulfates: jarosite, alunite, melanterite, copiapite and yavapaiite.
Caroll went on to complete a double when Godolphin's Alunite made all in the one-mile maiden.
Unidentified white, massive minerals of the alunite group occur as late-stage hydrothermal gangue in several veins.
Alunite is shaping up quite nicely, and he shared company with another who will hopefully be making waves in the shape of Equerry.
Alunite is a widespread and common mineral in the central core of the deposit, and is readily recognized by its pale pink to rose-pink color.
The bladed and spear-shaped crystals reach 4 mm in size, and occur as attractive clusters on what looks like tan-colored dolomite or alunite crystal-lined vugs and seams.
The mineralogy and geochemistry of this gossan have been described by Nickel (1982), who noted the occurrence of a number of secondary ore minerals including malachite, azurite, chrysocolla, pseudomalachite, cerussite, alunite, jarosite, plumbojarosite, osarizawaite, plumbogummite, duftite, mimetite, fornacite, wulfenite, mottramite, iodargyrite, native silver and a silver-mercury amalgam.
Drill target delineation and prioritization are based on critical technical characteristics which include a varying combination of a magnetic inversion low anomaly (possible magnetite destruction), silica and clay alteration (particularly high temperature clays such as alunite & advance argillic facies), permeable/reactive volcanic host rock or possible structure, prominent topographic linear, coincident surface soil-rock geochemical anomalies, nearby anomalous historical drill hole results and proximity to the Pueblo Viejo property's concealed Arroyo Hondo exploration target.
The Azerbaijan Industrial Corporation (AIC) has announced a tender for the selection of economically viable, environmentally friendly technologies, holding relevant laboratory and industrial tests, as well as preparing detailed feasibility study for obtaining the necessary concentrate of alunite, alumina and other semi-finished mineral products by alunite processing,Trendreports with reference to the AIC.