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 % Al₂O₃

Hydrogen 1.03 % H - % Calc as (NH₄)₂O

Hydrogen 1.54 % H 13.75 % H₂O

Sulfur 16.31 % S 40.73 % SO₃

Nitrogen 3.56 % N 6.62 % (NH₄)₂O

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 Kaolinite

Comments: White chalky ammonioalunite on darker kaolinite.
Location: Schoeller Mine, Kladno, Stredocesky, Czech Republic. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

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 3m

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 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:

PE_{Ammonioalunite}= 1.62 barns/electron
U=PE_{Ammonioalunite} x rElectron 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 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

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 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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Ammonioalunite

(NH4)Al3(SO4)2(OH)6
Dana No: 30.02.04.06 Strunz No: 07.BC.10
Locality:

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