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Alunite Mineral Data

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General Alunite Information

Help on Chemical  Formula: Chemical Formula: KAl3(SO4)2(OH)6
Help on Composition: Composition: Molecular Weight = 414.21 gm
   Potassium   9.44 %  K    11.37 % K2O
   Aluminum   19.54 %  Al   36.92 % Al2O3
   Hydrogen    1.46 %  H    13.05 % H2O
   Sulfur     15.48 %  S    38.66 % SO3
   Oxygen     54.08 %  O
             ______        ______ 
             100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: KAl3(SO4)2(OH)6
Help on Environment: Environment: Rock forming mineral where acid, often ore-bearing, solutions have altered orthoclase feldspar-rich rocks.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1824
Help on Locality: Locality: Marysvale, Utah. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: From the Latin alunit, meaning "alum."
Help on Name Pronunciation: Name Pronunciation: Alunite Say ALUNITE
Help on Synonym: Synonym: Aluminilite
  ICSD 12106
  PDF 13-136
 

Alunite Image

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  Alunite

Comments: Octahedral clear to tan tinted crystals of alunite.
Location: Marysvale, Piute County, Utah, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Alunite Crystallography

Help on Axial Ratios: Axial Ratios: a:c = 1:2.49354
Help on Cell Dimensions: Cell Dimensions: a = 6.97, c = 17.38, Z = 4; V = 731.22 Den(Calc)= 3.76
Help on Crystal System: Crystal System: Trigonal Space Group: R 3m, R 3m
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 2.89(1), 2.99(1), 2.293(0.8),
Help on Forms: Forms:

Mouse
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RMB - Cycle Display Modes
Drag1 - Manipulate Crystal
Drag2 - Resize

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I - Indicies
<space> - Start-Stop Rotation
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Help on Above

Forms: ( 0 1 2) ( 0 0 1)

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Physical Properties of Alunite

Help on Cleavage: Cleavage: {0001} Good
Help on Color: Color: White, Gray, Yellowish gray, Reddish gray, Yellowish white.
Help on Density: Density: 2.59 - 2.9, Average = 2.74
Help on Diaphaneity: Diaphaneity: Transparent to translucent
Help on Fracture: Fracture: Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern.
Help on Habit: Habit: Earthy - Dull, clay-like texture with no visible crystalline affinities, (e.g. howlite).
Help on Habit: Habit: Fibrous - Crystals made up of fibers.
Help on Habit: Habit: Massive - Granular - Common texture observed in granite and other igneous rock.
Help on Hardness: Hardness: 3.5-4 - Copper Penny-Fluorite
Help on Luminescence: Luminescence: Non-fluorescent.
Help on Luster: Luster: Vitreous - Pearly
Help on Streak: Streak: white
 

Optical Properties of Alunite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.002 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.268 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1548,KPDmeas= 0.212,KC= 0.2115
Ncalc = 1.55 - 1.8
Help on Optical Data: Optical Data: Uniaxial (+), w=1.572, e=1.592, bire=0.0200.
 

Calculated Properties of Alunite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.76 gm/cc
note: Specific Gravity of Alunite =2.75 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0014342941
Boson Index = 0.9985657059
Help on Photoelectric: Photoelectric: PEAlunite = 2.47 barns/electron
U=PEAlunite x relectron= 6.80 barns/cc.
Help on Radioactivity: Radioactivity:

GRapi = 136.78 (Gamma Ray American Petroleum Institute Units)
Concentration of Alunite per GRapi unit = 0.73 (%)

Estimated Radioactivity from Alunite - barely detectable

 

Alunite Classification

Help on  Dana Class: Dana Class: 30.02.04.01 (30)Anhydrous Sulfates Containing Hydroxyl or Halogen
  (30.02)where (A B)2 XO4 Zq
  (30.02.04)Alunite Group (Alunite Subgroup)
 
30.02.04.01 Alunite KAl3(SO4)2(OH)6 R 3m, R 3m Trig
 
30.02.04.02 Natroalunite NaAl3(SO4)2(OH)6 R 3m 3 2/m
 
30.02.04.03 Schlossmacherite (H3O,Ca)Al3(AsO4,SO4)2(OH)6 R 3m 3 2/m
 
30.02.04.04 Osarizawaite PbCuAl2(SO4)2(OH)6 R 3m 3m
 
30.02.04.05 Minamiite (Na,Ca,K)Al3(SO4)2(OH)6 R 3m 3 2/m
 
30.02.04.06 Ammonioalunite (NH4)Al3(SO4)2(OH)6 R 3m 3 2/m
 
30.02.04.07 Walthierite Ba0.5Al3(SO4)2(OH)6 R 3m 3 2/m
 
30.02.04.08 Huangite Ca0.5Al3(SO4)2(OH)6 R 3m 3 2/m
Help on  Strunz Class: Strunz Class: 07.BC.10 07 - SULFATES (SELENATES, TELLURATES)
  07.B - Sulfates (selenates, etc.) with Additional Anions, without H2O
  07.BC -With medium-sized and large cations
 
07.BC.10 Alunite KAl3(SO4)2(OH)6 R 3m, R 3m Trig
 
07.BC.10 Ammonioalunite (NH4)Al3(SO4)2(OH)6 R 3m 3 2/m
 
07.BC.10 Ammoniojarosite (NH4)Fe3(SO4)2(OH)6 R 3m 3m
 
07.BC.10 Beaverite PbCu(Fe,Al)2(SO4)2(OH)6 R 3m 3m
 
07.BC.10 Argentojarosite AgFe3(SO4)2(OH)6 R 3m 3m
 
07.BC.10 Huangite Ca0.5Al3(SO4)2(OH)6 R 3m 3 2/m
 
07.BC.10 Dorallcharite (Tl,K)Fe3(SO4)2(OH)6 R 3m 3 2/m
 
07.BC.10 Jarosite KFe3(SO4)2(OH)6 R 3 3
 
07.BC.10 Hydroniumjarosite (H3O)Fe3(SO4)2(OH)6 R 3m 3m
 
07.BC.10 Minamiite (Na,Ca,K)Al3(SO4)2(OH)6 R 3m 3 2/m
 
07.BC.10 Natrojarosite NaFe3(SO4)2(OH)6 R 3m 3m
 
07.BC.10 Natroalunite NaAl3(SO4)2(OH)6 R 3m 3 2/m
 
07.BC.10 Osarizawaite PbCuAl2(SO4)2(OH)6 R 3m 3m
 
07.BC.10 Plumbojarosite PbFe6(SO4)4(OH)12 R 3m 3 2/m
 
07.BC.10 Schlossmacherite (H3O,Ca)Al3(AsO4,SO4)2(OH)6 R 3m 3 2/m
 
07.BC.10 Walthierite Ba0.5Al3(SO4)2(OH)6 R 3m 3 2/m
 

Other Alunite Information

Help on References: References: NAME( Duda&Rejl90) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Mason68)
Help on See Also: See Also: Links to other databases for Alunite :
1 - Am. Min. Crystal Structure Database
2 - Amethyst Galleries' Mineral Gallery
3 - Athena
4 - EUROmin Project
5 - Ecole des Mines de Paris
6 - GeoScienceWorld
7 - Google Images
8 - Google Scholar
9 - Handbook of Mineralogy (MinSocAm)
10 - Handbook of Mineralogy (UofA)
11 - MinDAT
12 - Mineralienatlas (Deutsch)
13 - Online Mineral Museum
14 - Philatelic Mineralogy
15 - QUT Mineral Atlas
16 - Ruff.Info
17 - WWW-MINCRYST

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Alunite

KAl3(SO4)2(OH)6
Dana No: 30.02.04.01 Strunz No: 07.BC.10
Locality:

 

Notes:

 

 
   
 


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