alunite : List Of Minerals : The Stone Network
The Business To Business Portal For The Natural Stone Trade

Premium Black Galaxy Granite Slabs
Direct From The Factory
Ex-India



Stone Fairs

Exhibitions 2017 Country
Exhibitions 2017 By Date

Stone Images

Granite
Limestone
Marble
Onyx
Quartzite
Sandstone
Slate
Travertine

Stone Machines

New Stone Machines
Used Stone Machines

Stone Sites

Stone Forums
Stone Magazines
Stone Portals

Stone Standards

CE Marking

Stone Supplies & Fabricators

Australia
Canada
United Kingdom
U.S.A.

Stone Testing

6 Companies

Petrology

Granite
Limestone
Marble
Quartzite
Sandstone
Slate
Travertine

Rocks

Igneous
List of Minerals
List of Rocks
Metamorphic
Minerals
Sedimentary

Various Resources

A To Z Stone Names
Anti Slip
BIDA
Building Conservation
Building Design
English Heritage
Maintenance Products
Natural Stone Database
RIBA
RICS
Salvo
SPAB
Stone Federation GB
Trade Terminology

Alunite, or alumstone, is a mineral that was first observed in the 15th century in Monti della Tolfa, north to Rome, where it was mined for the manufacture of alum. First called aluminilite by J.C. Delametherie in 1707, this name was contracted by François Beudant in 1824 to alunite.

Distinct crystals of alunite are rarely found in cavities in the massive material. Alunite crystallizes in the hexagonal system with crystals forming trigonal pyramids that resemble rhombohedra with interfacial angles of 90 50', so that they resemble cubes in appearance. Minute glistening crystals have also been found loose in cavities in altered rhyolite. Alunite varies in color from white to yellow gray. The hardness is 4 and the specific gravity is between 2.6 and 2.8. The mineral is a hydrated aluminium potassium sulfate, KAl3(SO4)2(OH)6. Sodium substitutes for potassium and when high in sodium it is called natroalunite. It is insoluble in water or weak acids, but soluble in sulfuric acid. Jarosite is an iron analogue in which Fe3+ replaces the aluminium. It occurs as a secondary mineral on iron sulfate ores.

Alunite occurs as veins and replacement masses in trachyte, rhyolite, and similar potassium rich volcanic rocks It is formed by the action of sulfuric acid bearing solutions on these rocks during the oxidation and leaching of metal sulfide deposits. Alunite also is found near volcanic fumaroles. The white, finely granular masses closely resemble finely granular limestone, dolomite, anhydrite, and magnesite in appearance. The more compact kinds from Hungary are so hard and tough that they have been used for millstones.

Historically extensive deposits were mined in Tuscany and Hungary, and at Bulladelah in New South Wales. Currently found at Tolfa, Italy. In the United States it is found in the San Juan district of Colorado; Goldfield, Nevada; Marysvale, Utah; and Red Mountain in Patagonia, Arizona. The Arizona occurrence lies appropriately above a canyon named Alum Gulch. Alunite is mined as an ore of both potassium and aluminium at Marysvale. Some of the ore deposits were located by airborne and satellite multispectral imaging.

Trade Supplies
Information
Information
  • Absolute Black Granite : Black Galaxy, Star Galaxy, Nero Impala etc. Black is popular, black looks great, black is more expensive >>>
  • Black Galaxy Granite : Quarrying & Quality Information >>>
  • M.I.A. Information
    Copyright :
    Legal Information
    This web site is protected under International Law by the
    Digital Millennium Copyright Act 1998.

    If you wish to link to this site please feel free to do so HOWEVER blatant design copying, code copying and theft of bandwidth will result in legal action!

    Digg Logo ImageDigg Facebook Logo ImageFacebook Reddit Logo ImageReddit StumbleUpon Logo ImageStumbleUpon Twitter Logo ImageTwitter

    Home : Contact : About : Legal : Privacy : Cookies : Copyright 1998-2017 : The Stone Network