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Mohrite
A valid IMA mineral species
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About Mohrite
Karl Friedrich Mohr
Formula:
(NH4)2Fe(SO4)2 · 6H2O
Colour:
Pale green to colorless
Lustre:
Vitreous
Hardness:
2 - 2½
Specific Gravity:
1.800 - 1.862
Crystal System:
Monoclinic
Member of:
Name:
Named in 1964 by Carlo Lorenzo Garavelli in honor of Karl Friedrich Mohr [November 4, 1806 Koblenz, Germany â September 28, 1879], after whom the synthetic compound was originally named. Mohr was initially a business chemist, and he made many contributions to apparatus design, such as improved burets. His improvements to methods of volumetric analysis were important in quantitative chemical analysis. His theoretical contributions were very significant including his 1837 promulgation of a succinct description of the Conservation of Energy. Mohr was the author of books on chemistry as well as geology. Late in life, he came out of early retirement and worked as professor of pharmacy at the University of Bonn.
Type Locality:
Unique Identifiers
Mindat ID:
2742
Long-form identifier:
mindat:1:1:2742:3
Similar Names
| Marrite | A valid IMA mineral species - grandfathered | AgPbAsS3 |
| Meierite | A valid IMA mineral species | Ba44Si66Al30O192Cl25(OH)33 |
| Mohite | A valid IMA mineral species | Cu2SnS3 |
| Mohsite | A synonym of Dessauite-(Y) | |
| Mohsite (of Levy) | A synonym of Ilmenite | |
| Moiraite | A valid IMA mineral species - pending publication | Pb12Sb8As8S36 |
| Mooreite | A valid IMA mineral species - grandfathered | Mg9◻2Mn2Zn4(SO4)2(OH)26 · 8H2O |
| Mourite | A valid IMA mineral species | UMo5O12(OH)10 |
| Muirite | A valid IMA mineral species | Ba10(Ca2Mn2+Ti)[Si8O24]O2Cl10 |
| Möhnite | A valid IMA mineral species | (NH4)K2Na(SO4)2 |
IMA Classification of Mohrite
Classification of Mohrite
7.CC.60
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
C : Sulfates (selenates, etc.) without additional anions, with H2O
C : With medium-sized and large cations
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
C : Sulfates (selenates, etc.) without additional anions, with H2O
C : With medium-sized and large cations
29.3.7.1
29 : HYDRATED ACID AND NORMAL SULFATES
3 : A2B(XO4)2·xH2O
29 : HYDRATED ACID AND NORMAL SULFATES
3 : A2B(XO4)2·xH2O
25.11.16
25 : Sulphates
11 : Sulphates of Fe and other metals
25 : Sulphates
11 : Sulphates of Fe and other metals
Mineral Symbols
As of 2021 there are now IMAâCNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Mhr | IMAâCNMNC | Warr, L.N. (2021). IMAâCNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Mohrite
Vitreous
Transparency:
Transparent
Colour:
Pale green to colorless
Hardness:
2 - 2½ on Mohs scale
Cleavage:
Perfect
Perfect on {102}
Distinct on {010}
Perfect on {102}
Distinct on {010}
Density:
1.800 - 1.862 g/cm3 (Measured) 1.838(32) g/cm3 (Calculated)
Optical Data of Mohrite
Type:
Biaxial (+)
RI values:
nα = 1.48 - 1.486 nγ = 1.486 - 1.497
2V:
Measured: 65° to 75°
Max. Birefringence:
δ = 0.006 - 0.011
Based on recorded range of RI values above.
Based on recorded range of RI values above.
Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 ”m thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 ”m thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
Moderate (negative)
Relative to Canada balsam mounting medium (n ≈ 1.537).
Relative to Canada balsam mounting medium (n ≈ 1.537).
This shows the grain boundary and Becke line effect under plane-polarised
light, based on the contrast between this mineral's average refractive
index and the mounting medium. It does not take into account mineral
colouration.
In focus
Interference Figure:
This shows the idealized biaxial acute bisectrix (Bxa) interference figure
- the conoscopic view for a grain cut perpendicular to the acute bisectrix, using
this mineral's 2V. The two small white dots mark the melatopes - the points
where the two optic axes emerge - and are shown only when they fall within the
field of view. The coloured bands are isochromatics, and the dark bands are
isogyres.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Dispersion:
relatively strong
Chemistry of Mohrite
Mindat Formula:
(NH4)2Fe(SO4)2 · 6H2O
Element Weights:
Crystallography of Mohrite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P21/c
Setting:
P21/c
Cell Parameters:
a = 6.24(1) Å, b = 12.65(2) Å, c = 9.32(2) Å
β = 106.79°
β = 106.79°
Ratio:
a:b:c = 0.493 : 1 : 0.737
Unit Cell V:
704.32 Ă
Âł (Calculated from Unit Cell)
Z:
2
Morphology:
Subhedral crystals, irregular lamellae
Comment:
Synthetic
Crystal Structure
Load
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
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CIF File Best | x | y | z | a | b | c
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Labels
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Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure
| ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
|---|---|---|---|---|---|---|---|
| 0010076 | Mohrite | Figgis B N, Kucharski E S, Reynolds P A, Tasset F (1989) The structure of (ND4)2Fe(SO4)2*6D2O at 4.3 K by neutron diffraction Acta Crystallographica C45 942-944 |  | 1989 | synthetic | 0 | 293 |
CIF Raw Data - click here to close
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 45a : [Sulfates, arsenates, selenates, antimonates] | |
| 45b : [Other oxidized fumarolic minerals] |
Geological Setting:
Boriferous fumaroles and geysers.
Type Occurrence of Mohrite
Synonyms of Mohrite
Other Language Names for Mohrite
Dutch:Mohriet
German:Mohrit
Simplified Chinese:ć
æ°Žé”éçŸ
Spanish:Mohrita
Traditional Chinese:ć
æ°Žéšé”瀏
Relationship of Mohrite to other Species
Member of:
Other Members of Picromerite Group:
| Boussingaultite | (NH4)2Mg(SO4)2 · 6H2O | Mon. 2/m : P21/c |
| Cyanochroite | K2Cu(SO4)2 · 6H2O | Mon. 2/m : P21/c |
| Katerinopoulosite | (NH4)2Zn(SO4)2 · 6H2O | Mon. 2/m : P21/c |
| Nickelboussingaultite | (NH4)2Ni(SO4)2 · 6H2O | Mon. 2/m : P21/c |
| Nickelpicromerite | K2Ni(SO4)2 · 6H2O | Mon. 2/m : P21/c |
| Picromerite | K2Mg(SO4)2 · 6H2O | Mon. 2/m : P2/b |
Forms a series with:
Common Associates
Associations Based on Photo Data:
| 4 photos of Mohrite associated with Tschermigite | (NH4)Al(SO4)2 · 12H2O |
| 2 photos of Mohrite associated with Mascagnite | (NH4)2SO4 |
| 1 photo of Mohrite associated with Pyrite | FeS2 |
Related Minerals - Strunz-mindat Grouping
| 7.CC. | Cobaltoblödite | Na2Co(SO4)2 · 4H2O |
| 7.CC. | Andychristyite | PbCu2+Te6+O5(H2O) |
| 7.CC. | Ammoniovoltaite | (NH4)2Fe2+5Fe3+3Al(SO4)12(H2O)18 |
| 7.CC.05 | Krausite | KFe(SO4)2 · H2O |
| 7.CC.10 | Tamarugite | NaAl(SO4)2 · 6H2O |
| 7.CC.15 | Mendozite | NaAl(SO4)2 · 11H2O |
| 7.CC.15 | Kalinite | KAl(SO4)2 · 11H2O |
| 7.CC.20 | Alum-(Na) | NaAl(SO4)2 · 12H2O |
| 7.CC.20 | Lonecreekite | (NH4)Fe3+(SO4)2 · 12H2O |
| 7.CC.20 | Alum-(K) | KAl(SO4)2 · 12H2O |
| 7.CC.20 | Tschermigite | (NH4)Al(SO4)2 · 12H2O |
| 7.CC.20 | Lanmuchangite | Tl+Al(SO4)2 · 12H2O |
| 7.CC.25 | Zincovoltaite | K2Zn5Fe3+3Al(SO4)12 · 18H2O |
| 7.CC.25 | Voltaite | K2Fe2+5Fe3+3Al(SO4)12 · 18H2O |
| 7.CC.25 | Magnesiovoltaite | K2Mg5Fe3+3Al(SO4)12 · 18H2O |
| 7.CC.25 | Pertlikite | K2(Fe2+,Mg)2(Mg,Fe3+)4Fe3+2Al(SO4)12 · 18H2O |
| 7.CC.25 | Ammoniomagnesiovoltaite | (NH4)2Mg2+5Fe3+3Al(SO4)12 · 18H2O |
| 7.CC.30 | Kröhnkite | Na2Cu(SO4)2 · 2H2O |
| 7.CC.35 | Ferrinatrite | Na3Fe(SO4)3 · 3H2O |
| 7.CC.40 | Goldichite | KFe(SO4)2 · 4H2O |
| 7.CC.45 | Löweite | Na12Mg7(SO4)13 · 15H2O |
| 7.CC.50 | Nickelblödite | Na2Ni(SO4)2 · 4H2O |
| 7.CC.50 | Blödite | Na2Mg(SO4)2 · 4H2O |
| 7.CC.50 | Changoite | Na2Zn(SO4)2 · 4H2O |
| 7.CC.55 | Leonite | K2Mg(SO4)2 · 4H2O |
| 7.CC.55 | Mereiterite | K2Fe(SO4)2 · 4H2O |
| 7.CC.60 | Nickelpicromerite | K2Ni(SO4)2 · 6H2O |
| 7.CC.60 | Nickelboussingaultite | (NH4)2Ni(SO4)2 · 6H2O |
| 7.CC.60 | Katerinopoulosite | (NH4)2Zn(SO4)2 · 6H2O |
| 7.CC.60 | Picromerite | K2Mg(SO4)2 · 6H2O |
| 7.CC.60 | Cyanochroite | K2Cu(SO4)2 · 6H2O |
| 7.CC.60 | Boussingaultite | (NH4)2Mg(SO4)2 · 6H2O |
| 7.CC.65 | Polyhalite | K2Ca2Mg(SO4)4 · 2H2O |
| 7.CC.70 | Leightonite | K2Ca2Cu(SO4)4 · 2H2O |
| 7.CC.75 | Amarillite | NaFe(SO4)2 · 6H2O |
| 7.CC.80 | Konyaite | Na2Mg(SO4)2 · 5H2O |
| 7.CC.85 | Wattevilleite | Na2Ca(SO4)2 · 4H2O (?) |
| 7.CC.85 | Xocolatlite | Ca2Mn4+2(Te6+O6)2 · H2O |
| 7.CC.90 | Eckhardite | (Ca,Pb)Cu2+Te6+O5(H2O) |
Other Information
Notes:
Soluble in water
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Internet Links for Mohrite
mindat.org URL:
https://www.mindat.org/min-2742.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Mohrite
Reference List:
Localities for Mohrite
Showing 22 localities.
symbol to view information about a locality.
The Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
â - Click for references and further information on this occurrence.
? - Indicates mineral may be doubtful at this locality.
- Good crystals or important locality for species.
- World class for species or very significant.
(TL) - Type Locality for a valid mineral species.
(FRL) - First Recorded Locality for everything else (eg varieties).
All localities listed without proper references should be considered as questionable.
Canada | |
| HorvĂĄth (2007) |
| Greengrass et al. (1999) |
Czech Republic | |
| JirĂĄsek (2001) |
| PlĂĄĆĄil et al. (2006) |
| Sejkora et al. (2006) |
| Scharm +7 other references |
| MatĂœsek et al. (2022) |
Germany | |
| Walenta (1992) |
Hungary | |
| GEODA 2007/1 |
| SzakĂĄll et al. (2008) |
Italy (TL) | |
| Garavelli (1964) |
Kenya | |
| Bowell et al. (1996) |
New Zealand | |
| Johnstone (1979) |
| Johnstone (1979) | |
Peru | |
| Ciesielczuk et al. (2013) |
Poland | |
| Kruszewski et al. (2020) |
| Kruszewski (2012) |
| Kruszewski et al. (2020) |
| Kruszewski et al. (2018) |
Russia | |
| Cesnokov et al. (1998) |
Switzerland | |
| Analyses by N. Meisser (Musée cantonal de géologie, Lausanne) |
USA | |
| Hower et al. (2013) |
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Shaft No. III, KomlĂł, KomlĂł District, Baranya County, Hungary