Ammonioalunite Mineral Data
General Ammonioalunite Information
Chemical Formula:
(NH4)Al3(SO4)2(OH)6
Composition:
Molecular Weight = 393.15 gm
Aluminum 20.59 % Al 38.90 % Al2 O3
Hydrogen 1.03 % H - % Calc as (NH4 )2 O
Hydrogen 1.54 % H 13.75 % H2 O
Sulfur 16.31 % S 40.73 % SO3
Nitrogen 3.56 % N 6.62 % (NH4 )2 O
Oxygen 56.97 % O
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:
(NH4 )Al3 (SO4 )2 (OH)6
Environment:
Acidic hot springs with temperatures below 100 deg C and low potassium content of the waters.
IMA Status:
Approved IMA 1987
Locality:
The Geysers, Sonoma County, California, USA. Link to MinDat.org Location Data.
Name Origin:
Named for its composition (Ammonia, Al,).
Name Pronunciation:
Ammonioalunite + Pronunciation
Ammonioalunite Image
Images:
Ammonioalunite Crystallography
Axial Ratios:
a:c = 1:2.55026
Cell Dimensions:
a = 7.013, c = 17.885, Z = 3; V = 761.78 Den(Calc)= 2.57
Crystal System:
Trigonal - Hexagonal Scalenohedral H-M Symbol (3 2/m) Space Group: R 3 m
X Ray Diffraction:
By Intensity(I/Io ): 3.023(1), 5.04(0.93), 2.996(0.5),
Physical Properties of Ammonioalunite
Cleavage:
{???} Good
Color:
Gray white, White.
Density:
2.4
Diaphaneity:
Transparent to Translucent
Habit:
Efflorescences - Crystals covering matrix, generally produced from transpiro-evaporation.
Habit:
Massive - Granular - Common texture observed in granite and other igneous rock.
Habit:
Rhombohedral Crystals - Occurs as well-formed crystals showing rhobohedral crystals.
Hardness:
2-3 - Gypsum-Calcite
Luminescence:
Non-fluorescent.
Luster:
Vitreous (Glassy)
Streak:
white
Optical Properties of Ammonioalunite
Gladstone-Dale:
CI meas = -0.246 (Poor) - where the CI = (1-KPDmeas /KC ) CI calc = -0.163 (Poor) - where the CI = (1-KPDcalc /KC )
KPDcalc = 0.2319,KPDmeas = 0.2483,KC = 0.1994 Ncalc = 1.48 - 1.51
Optical Data:
Uniaxial (+), w=1.59, e=1.602, bire=0.0120.
Calculated Properties of Ammonioalunite
Electron Density:
Bulk Density (Electron Density)=2.61 gm/cc note: Specific Gravity of Ammonioalunite =2.57 gm/cc.
Fermion Index:
Fermion Index = 0.03 Boson Index = 0.97
Photoelectric:
PEAmmonioalunite = 1.62 barns/electronU=PEAmmonioalunite x r Electron Density= 4.24 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Ammonioalunite is Not Radioactive
Ammonioalunite Classification
Dana Class:
30.02.04.06 (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 3 m Trig
30.02.04.02 Natroalunite NaAl3(SO4)2(OH)6 R 3 m 3 2/m
30.02.04.03 Schlossmacherite (H3O,Ca)Al3(AsO4,SO4)2(OH)6 R 3 m 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 3 m 3 2/m
30.02.04.06 Ammonioalunite (NH4)Al3(SO4)2(OH)6 R 3 m 3 2/m
30.02.04.07 Walthierite Ba0.5Al3(SO4)2(OH)6 R 3 m 3 2/m
30.02.04.08 Huangite Ca0.5Al3(SO4)2(OH)6 R 3 m 3 2/m
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 3 m Trig
07.BC.10 Ammonioalunite (NH4)Al3(SO4)2(OH)6 R 3 m 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 3 m 3 2/m
07.BC.10 Dorallcharite (Tl,K)Fe3(SO4)2(OH)6 R 3 m 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 3 m 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 3 m 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 3 m 3 2/m
07.BC.10 Schlossmacherite (H3O,Ca)Al3(AsO4,SO4)2(OH)6 R 3 m 3 2/m
07.BC.10 Walthierite Ba0.5Al3(SO4)2(OH)6 R 3 m 3 2/m
Other Ammonioalunite Information
References:
NAME( Dana8) PHYS. PROP.(Dana8) OPTIC PROP.(Am.Min.,Vol.73,p145-152,1988)
See Also:
Links to other databases for Ammonioalunite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - GeoScienceWorld
6 - Google Images
7 - Google Scholar
8 - Handbook of Mineralogy (MinSocAm)
9 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info
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Print or Cut-and-Paste your Ammonioalunite Specimen Label here :
Ammonioalunite
(NH4)Al3(SO4)2(OH)6
Dana No: 30.02.04.06 Strunz No: 07.BC.10
Locality:
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