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Hohmannite Mineral Data

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General Hohmannite Information

Help on Chemical  Formula: Chemical Formula: Fe+++2(SO4)2(OH)2•7(H2O)
Help on Composition: Composition: Molecular Weight = 463.94 gm
   Iron      24.07 %  Fe   34.42 % Fe2O3
   Hydrogen   3.48 %  H    31.06 % H2O
   Sulfur    13.82 %  S    34.51 % SO3
   Oxygen    58.63 %  O
            ______        ______ 
            100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Fe3+2(SO4)2(OH)2•7(H2O)
Help on Environment: Environment: Low-temperature precipitate in oxidized iron sulfide deposits.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1888
Help on Locality: Locality: Antofagasta, from near Caracoles, Sierra Gorda district, Chile. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Thomas Hohmann (1843-1897), mining engineer of Valparaiso, Chile who discovered the first specimens.
Help on Name Pronunciation: Name Pronunciation: Hohmannite + Pronunciation Say HOHMANNITE
Help on Synonym: Synonym: Castanite
  ICSD 37328
  PDF 17-155

Hohmannite Image

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  Hohmannite   Metahohmannite

Comments: Orange opaque prismatic microcrystals of hohmannite mixed with yellow metahohmanite.
Location: Chuquicamata, Antofagasta, Chile. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Hohmannite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.8318:1:0.659
Help on Cell Dimensions: Cell Dimensions: a = 9.05, b = 10.88, c = 7.17, Z = 2; alpha = 90.15°, beta = 90.58°, gamma = 107° V = 675.10 Den(Calc)= 2.28
Help on Crystal System: Crystal System: Triclinic - Pinacoidal H-M Symbol ( 1) Space Group: P1
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 7.92(1), 8.69(0.8), 10.4(0.6),

Physical Properties of Hohmannite

Help on Cleavage: Cleavage: {???} Perfect, {???} Imperfect
Help on Color: Color: Brown, Orange brown, Reddish brown.
Help on Density: Density: 2.2
Help on Diaphaneity: Diaphaneity: Transparent to Translucent
Help on Hardness: Hardness: 3 - Calcite
Help on Luminescence: Luminescence: Non-fluorescent.
Help on Luster: Luster: Vitreous (Glassy)
Help on Streak: Streak: orange

Optical Properties of Hohmannite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.023 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= 0.013 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2715,KPDmeas= 0.2814,KC= 0.2751
Ncalc = 1.61 - 1.63
Help on Optical Data: Optical Data: Biaxial (-), a=1.559, b=1.643, g=1.655, bire=0.0960

Calculated Properties of Hohmannite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.32 gm/cc
note: Specific Gravity of Hohmannite =2.28 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0064272507
Boson Index = 0.9935727493
Help on Photoelectric: Photoelectric: PEHohmannite = 7.83 barns/electron
U=PEHohmannite x rElectron Density= 18.16 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Hohmannite is Not Radioactive

Hohmannite Classification

Help on  Dana Class: Dana Class: (31)Hydrated Sulfates Containing Hydroxyl or Halogen
  (31.09)where (A+ B++) (XO4) Zq�x(H2O)
  (31.09.04)Dana Group Hohmannite Fe2(SO4)2(OH)2•7(H2O) P1 1
Help on  Strunz Class: Strunz Class: 07.DB.30 07 - SULFATES (SELENATES, TELLURATES)
  07.D - Sulfates (selenates, etc.) with additional anions, with H2O
  07.DB -With only medium-sized cations; insular octahedra and finite groups
07.DB.30 Amarantite Fe(SO4)(OH)•3(H2O) P1 1
07.DB.30 Hohmannite Fe2(SO4)2(OH)2•7(H2O) P1 1
07.DB.30 Metahohmannite Fe2[O(SO4)2]•4(H2O) P1 1

Other Hohmannite Information

Help on References: References: NAME( AntBidBlaNic5) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)
Help on See Also: See Also: Links to other databases for Hohmannite :
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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Dana No: Strunz No: 07.DB.30





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