Metahohmannite
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About Metahohmannite
Formula:
Fe3+2(SO4)2O · 4H2O
Colour:
Orange
Crystal System:
Triclinic
Name:
The name is derived from 'meta', for its lower hydration level, and its relationship to hohmannite.
Classification of Metahohmannite
Approved, 'Grandfathered' (first described prior to 1959)
6/D.01-35
7.DB.30
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
D : Sulfates (selenates, etc.) with additional anions, with H2O
B : With only medium-sized cations; insular octahedra and finite units
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
D : Sulfates (selenates, etc.) with additional anions, with H2O
B : With only medium-sized cations; insular octahedra and finite units
31.9.5.1
31 : HYDRATED SULFATES CONTAINING HYDROXYL OR HALOGEN
9 : (AB)(XO4)Zq·xH2O
31 : HYDRATED SULFATES CONTAINING HYDROXYL OR HALOGEN
9 : (AB)(XO4)Zq·xH2O
25.10.13
25 : Sulphates
10 : Sulphates of Fe alone
25 : Sulphates
10 : Sulphates of Fe alone
Physical Properties of Metahohmannite
Colour:
Orange
Optical Data of Metahohmannite
Type:
Biaxial (+)
RI values:
nα = 1.709 nβ = 1.718 nγ = 1.734
2V:
Measured: 70° , Calculated: 76°
Max Birefringence:
δ = 0.025

Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
and does not take into account mineral colouration.
Surface Relief:
High
Dispersion:
r > v weak
Pleochroism:
Visible
Comments:
X = Light yellow
Y = Reddish yellow
Z = Reddish brown
Y = Reddish yellow
Z = Reddish brown
Chemical Properties of Metahohmannite
Formula:
Fe3+2(SO4)2O · 4H2O
IMA Formula:
Fe3+2O(SO4)2 · 4H2O
Elements listed:
Crystallography of Metahohmannite
Crystal System:
Triclinic
Class (H-M):
1 - Pinacoidal
Space Group:
P1
Cell Parameters:
a = 7.3484(5) Å, b = 9.7710(6) Å, c = 7.1521(5) Å
α = 91.684(5)°, β = 98.523(5)°, γ = 86.390(5)°
α = 91.684(5)°, β = 98.523(5)°, γ = 86.390(5)°
Ratio:
a:b:c = 0.752 : 1 : 0.732
Unit Cell V:
506.75 ų (Calculated from Unit Cell)
Morphology:
Pulverulent masses.
Comment:
Non-standard setting.
Type Occurrence of Metahohmannite
Other Language Names for Metahohmannite
Common Associates
Associated Minerals Based on Photo Data:
Hohmannite | 1 photo of Metahohmannite associated with Hohmannite on mindat.org. |
Amarantite | 1 photo of Metahohmannite associated with Amarantite on mindat.org. |
Fibroferrite | 1 photo of Metahohmannite associated with Fibroferrite on mindat.org. |
Copiapite | 1 photo of Metahohmannite associated with Copiapite on mindat.org. |
Related Minerals - Nickel-Strunz Grouping
7.DB.05 | Aubertite | CuAl(SO4)2Cl · 14H2O | Tric. 1 |
7.DB.05 | Magnesioaubertite | (Mg,Cu)Al(SO4)2Cl · 14H2O | |
7.DB.05 | Svyazhinite | (Mg,Mn2+,Ca)(Al,Fe3+)(SO4)2F · 14H2O | Tric. |
7.DB.10 | Khademite | Al(SO4)F · 5H2O | Orth. mmm (2/m 2/m 2/m) |
7.DB.10 | Rostite | Al(SO4)(OH) · 5H2O | Orth. mmm (2/m 2/m 2/m) |
7.DB.15 | Jurbanite | Al(SO4)(OH) · 5H2O | Mon. |
7.DB.20 | Minasragrite | (V4+O)(SO4) · 5H2O | Mon. 2/m |
7.DB.20 | Orthominasragrite | (V4+O)(SO4) · 5H2O | Orth. mm2 : Pmn21 |
7.DB.20 | Anorthominasragrite | (V4+O)(SO4) · 5H2O | Tric. 1 : P1 |
7.DB.25 | Bobjonesite | (V4+O)(SO4) · 3H2O | Mon. 2/m |
7.DB.30 | Amarantite | Fe3+2(SO4)2O · 7H2O | Tric. 1 |
7.DB.30 | Hohmannite | Fe3+2(SO4)2O · 8H2O | Tric. 1 |
7.DB.35 | Aluminocopiapite | Al2/3Fe3+4(SO4)6(OH)2 · 20H2O | Tric. 1 : P1 |
7.DB.35 | Calciocopiapite | CaFe4(SO4)6(OH)2 · 10H2O | Tric. 1 : P1 |
7.DB.35 | Copiapite | Fe2+Fe3+4(SO4)6(OH)2 · 20H2O | Tric. 1 : P1 |
7.DB.35 | Cuprocopiapite | CuFe4(SO4)6(OH)2 · 20H2O | Tric. 1 : P1 |
7.DB.35 | Ferricopiapite | Fe5(SO4)6O(OH) · 20H2O | Tric. 1 : P1 |
7.DB.35 | Magnesiocopiapite | MgFe3+4(SO4)6(OH)2 · 20H2O | Tric. 1 : P1 |
7.DB.35 | Zincocopiapite | ZnFe3+4(SO4)6(OH)2 · 18H2O | Tric. |
Related Minerals - Hey's Chemical Index of Minerals Grouping
25.10.1 | Szomolnokite | FeSO4 · H2O | Mon. 2/m : B2/b |
25.10.2 | Rozenite | FeSO4 · 4H2O | Mon. 2/m : P21/b |
25.10.3 | Siderotil | FeSO4 · 5H2O | Tric. |
25.10.4 | Ferrohexahydrite | FeSO4 · 6H2O | Mon. 2/m : B2/b |
25.10.5 | Melanterite | Fe2+(H2O)6SO4 · H2O | Mon. 2/m : P21/b |
25.10.6 | Rhomboclase | (H5O2)Fe3+(SO4)2 · 2H2O | Orth. mmm (2/m 2/m 2/m) : Pnma |
25.10.7 | Lausenite | Fe2(SO4)3·5H2O | Mon. 2/m : P21/m |
25.10.8 | Kornelite | Fe2(SO4)3 · 7H2O | Mon. 2/m : P21/m |
25.10.9 | Coquimbite | Fe2-xAlx(SO4)3 · 9H2O, x ~0.5 | Trig. 3m (3 2/m) : P3 1c |
25.10.10 | Paracoquimbite | Fe2(SO4)3 · 9H2O | Trig. 3 : R3 |
25.10.11 | Quenstedtite | Fe2(SO4)3 · 11H2O | Tric. 1 : P1 |
25.10.12 | Ferricopiapite | Fe5(SO4)6O(OH) · 20H2O | Tric. 1 : P1 |
25.10.14 | Hohmannite | Fe3+2(SO4)2O · 8H2O | Tric. 1 |
25.10.15 | Butlerite | Fe3+(SO4)(OH) · 2H2O | Mon. 2/m : P21/m |
25.10.16 | Parabutlerite | Fe3+(SO4)(OH) · 2H2O | Orth. mmm (2/m 2/m 2/m) |
25.10.17 | Amarantite | Fe3+2(SO4)2O · 7H2O | Tric. 1 |
25.10.18 | Fibroferrite | Fe3+(SO4)(OH) · 5H2O | Mon. |
25.10.19 | Hydroniumjarosite | (H3O)Fe3+3(SO4)2(OH)6 | Trig. 3m (3 2/m) : R3m |
25.10.20 | Römerite | Fe2+Fe3+2(SO4)4 · 14H2O | Tric. 1 : P1 |
25.10.21 | Bílinite | Fe2+Fe3+2(SO4)4 · 22H2O | Mon. 2/m : P21/b |
25.10.22 | Copiapite | Fe2+Fe3+4(SO4)6(OH)2 · 20H2O | Tric. 1 : P1 |
Other Information
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
References for Metahohmannite
Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
Mackintosh, James B. (1889) Notes on some Native Iron Sulphates from Chili. American Journal of Science: 38: 242-245 (material may not be identical to metahohmannite).
Bandy, M.C. (1938) Mineralogy of three sulphate deposits of Northern Chile. American Mineralogist: 23: 669-760.
Ungemach (1935) Bulletin de la Société française de Minéralogie: 58: 97.
Palache, C., Berman, H., Frondel, C. (1951) The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume II. John Wiley and Sons, Inc., New York, 7th edition, revised and enlarged, 1124 pp.: 608.
Scordari, F., Ventruti, G., Gualtieri, A.F. (2004) The structure of metahohmannite, Fe23+[O(SO4)2].4H2O, by in situ synchrotron powder diffraction. American Mineralogist: 89: 365-370.
Internet Links for Metahohmannite
mindat.org URL:
https://www.mindat.org/min-2675.html
Please feel free to link to this page.
Please feel free to link to this page.
External Links:
Mineral Dealers:
Localities for Metahohmannite
Locality List




All localities listed without proper references should be considered as questionable.
Australia | |
| Noble R.J, Just J, Johnson J. E. (1983), Catalogue of South Australian Minerals - 1983, Govenment Printer, South Australia. |
Chile | |
| Palache, C., Berman, H., & Frondel, C. (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume II: 608.; Kampf, A.R.; Mills, S.J.; Housley, R.M.; Williams, P.A.; Dini, M. (2012): Alcaparrosaite, K3Ti4+Fe3+(SO4)4O(H2O)2, a new hydrophobic Ti4+ sulfate from Alcaparrosa, Chile. Mineralogical Magazine 76, 851-861. |
| American Mineralogist (1938): 23: 748; Palache, C., Berman, H., & Frondel, C. (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume II: 608. |
| Palache, C., Berman, H., & Frondel, C. (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume II: 608. |
| Peter G. Seroka collection |
Greece | |
| Rieck, B., Kolitsch, U., Voudouris, P., Giester, G. and Tzeferis, P. (2018): Weitere Neufunde aus Lavrion, Griechenland. Mineralien-Welt 29 (5), 32-77 (in German). |
| Rieck, B., Kolitsch, U., Voudouris, P., Giester, G. and Tzeferis, P. (2018): Weitere Neufunde aus Lavrion, Griechenland. Mineralien-Welt 29 (5), 32-77 (in German). |
USA | |
| Chemical Geology Volume 215, Issues 1-4, 15 February 2005, Pages 433-452 |
Queténa Mine, Toki Cu deposit, Chuquicamata District, Calama, El Loa Province, Antofagasta, Chile