Manganohörnesite
A valid IMA mineral species - grandfathered
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About Manganohörnesite
Formula:
Mn2+3(AsO4)2 · 8H2O
May contain some Mg replacing Mn.
Colour:
White to colorless
Lustre:
Silky
Hardness:
1
Specific Gravity:
2.64
Crystal System:
Monoclinic
Member of:
Name:
Originally named manganese-hoernesite in 1951 by Olof Gabrielson for being the manganese analogue of hornesite (now hörnesite). It was renamed by the IMA (Burke 2008) to manganohörnesite.
Isostructural with:
Vivianite Group. Related to monteneroite.
A lower hydrate (tetrahydrate) is castellaroite.
Crystals of manganohörnesite may resemble hörnesite and gypsum.
A lower hydrate (tetrahydrate) is castellaroite.
Crystals of manganohörnesite may resemble hörnesite and gypsum.
Name Encoding
ASCII-7:
Manganohornesite
Unique Identifiers
Mindat ID:
2495
Long-form identifier:
mindat:1:1:2495:8
IMA Classification of Manganohörnesite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
Mn2+3(As5+O4)2·8H2O
First published:
1951
Classification of Manganohörnesite
8.CE.40
8 : PHOSPHATES, ARSENATES, VANADATES
C : Phosphates without additional anions, with H2O
E : With only medium-sized cations, RO4:H2O about 1:2.5
8 : PHOSPHATES, ARSENATES, VANADATES
C : Phosphates without additional anions, with H2O
E : With only medium-sized cations, RO4:H2O about 1:2.5
40.3.7.2
40 : HYDRATED NORMAL PHOSPHATES,ARSENATES AND VANADATES
3 : A3(XO4)2·xH2O
40 : HYDRATED NORMAL PHOSPHATES,ARSENATES AND VANADATES
3 : A3(XO4)2·xH2O
20.8.12
20 : Arsenates (also arsenates with phosphate, but without other anions)
8 : Arsenates of Mn
20 : Arsenates (also arsenates with phosphate, but without other anions)
8 : Arsenates of Mn
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Mhns | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Manganohörnesite
Silky
Transparency:
Transparent
Comment:
Because of common acicular habit
Colour:
White to colorless
Streak:
White
Hardness:
1 on Mohs scale
Tenacity:
Flexible
Cleavage:
Perfect
{01`0} perfect, poor on {100}, {201}, {201}
{01`0} perfect, poor on {100}, {201}, {201}
Density:
2.64 g/cm3 (Measured) 2.76 g/cm3 (Calculated)
Optical Data of Manganohörnesite
Type:
Biaxial (+)
RI values:
nα = 1.579 nβ = 1.589 nγ = 1.609
2V:
Measured: 65° to 70°, Calculated: 72°
Birefringence:
0.030
Max. Birefringence:
δ = 0.030
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 µm 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 µm 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 (positive)
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:
very weak
Optical Extinction:
Z nearly = c
Pleochroism:
Not Visible
Chemistry of Manganohörnesite
Mindat Formula:
Mn2+3(AsO4)2 · 8H2O
May contain some Mg replacing Mn.
May contain some Mg replacing Mn.
Element Weights:
Elements listed:
Crystallography of Manganohörnesite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P2/m
Setting:
P2/m
Cell Parameters:
a = 10.385 Å, b = 28.095 Å, c = 4.774 Å
β = 105.67°
β = 105.67°
Ratio:
a:b:c = 0.37 : 1 : 0.17
Unit Cell V:
1,341.12 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Usually acicular; needle-like crystals or elongated crystals flattened along (010): As star-like aggregates.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 8.19 Å | (80) |
| 7.01 Å | (100) |
| 3.25 Å | (60) |
| 3.09 Å | (60) |
| 3.02 Å | (70) |
| 2.88 Å | (40) |
| 2.72 Å | (40) |
| 2.41 Å | (70) |
Comments:
ICDD 8-141
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| High-? alteration and/or metamorphism | |
| 31 : Thermally altered carbonate, phosphate, and iron formations | |
| 32 : Ba/Mn/Pb/Zn deposits, including metamorphic deposits |
Geological Setting:
Fractures in manganese-bearing ores
Type Occurrence of Manganohörnesite
General Appearance of Type Material:
Crusts in fissures.
Geological Setting of Type Material:
Fractures in manganese skarn
Associated Minerals at Type Locality:
Synonyms of Manganohörnesite
Other Language Names for Manganohörnesite
Relationship of Manganohörnesite to other Species
Member of:
Other Members of Vivianite Group:
| Annabergite | Ni3(AsO4)2 · 8H2O | Mon. 2/m : B2/m |
| Arupite | Ni3(PO4)2 · 8H2O | Mon. 2/m : B2/m |
| Babánekite | Cu3(AsO4)2 · 8H2O | Mon. 2/m : B2/m |
| Barićite | (Mg,Fe)3(PO4)2 · 8H2O | Mon. 2/m : B2/m |
| Cabrerite | NiMg2(AsO4)2 · 8H2O | Mon. 2/m : B2/m |
| Erythrite | Co3(AsO4)2 · 8H2O | Mon. 2/m : B2/m |
| Gritsenkoite | CoMg2(AsO4)2(H2O)8 | Mon. 2/m : B2/m |
| Hörnesite | Mg3(AsO4)2 · 8H2O | Mon. 2/m : B2/m |
| Köttigite | Zn3(AsO4)2 · 8H2O | Mon. 2/m : B2/m |
| Monteneroite | Cu2+Mn2+2(AsO4)2 · 8H2O | Mon. 2/m : B2/m |
| Pakhomovskyite | Co3(PO4)2 · 8H2O | Mon. 2/m : B2/m |
| Parasymplesite | Fe2+3(AsO4)2 · 8H2O | Mon. 2/m : B2/m |
| Vivianite | Fe2+Fe2+2(PO4)2 · 8H2O | Mon. 2/m : B2/m |
| Zincocabrerite | ZnMg2(AsO4)2(H2O)8 | Mon. 2/m : B2/m |
Common Associates
Associations Based on Photo Data:
| 5 photos of Manganohörnesite associated with Hausmannite | Mn2+Mn3+2O4 |
| 5 photos of Manganohörnesite associated with Dolomite | CaMg(CO3)2 |
| 2 photos of Manganohörnesite associated with Adelite | CaMg(AsO4)(OH) |
| 2 photos of Manganohörnesite associated with Akrochordite | MnMn2Mn2(AsO4)2(OH)4(H2O)4 |
| 2 photos of Manganohörnesite associated with Franklinite | Zn2+Fe3+2O4 |
| 2 photos of Manganohörnesite associated with Willemite | Zn2SiO4 |
| 1 photo of Manganohörnesite associated with Hematite | Fe2O3 |
| 1 photo of Manganohörnesite associated with Långbanshyttanite | Pb2Mn2Mg(AsO4)2(OH)4 · 6H2O |
| 1 photo of Manganohörnesite associated with Hörnesite | Mg3(AsO4)2 · 8H2O |
| 1 photo of Manganohörnesite associated with Baryte | BaSO4 |
Related Minerals - Strunz-mindat Grouping
| 8.CE. | Monteneroite | Cu2+Mn2+2(AsO4)2 · 8H2O |
| 8.CE. | Belmonteite | CaMn2(AsO4)2 · 7H2O |
| 8.CE. | Zincocabrerite | ZnMg2(AsO4)2(H2O)8 |
| 8.CE.X | Babánekite | Cu3(AsO4)2 · 8H2O |
| 8.CE.05 | Chudobaite | Mg5(AsO4)2(AsO3OH)2 · 10H2O |
| 8.CE.05 | Geigerite | Mn2+5(AsO4)2(HAsO4)2 · 10H2O |
| 8.CE.10 | Newberyite | Mg(PO3OH) · 3H2O |
| 8.CE.10 | Manganonewberyite | Mn(PO3OH)(H2O)3 |
| 8.CE.15 | Fanguangite | (MoO2)(PO3OH) · 4H2O |
| 8.CE.15 | Brassite | Mg(HAsO4) · 4H2O |
| 8.CE.20 | Phosphorrösslerite | Mg(PO3OH) · 7H2O |
| 8.CE.20 | Rösslerite | Mg(HAsO4) · 7H2O |
| 8.CE.25 | Switzerite | Mn2+3(PO4)2 · 7H2O |
| 8.CE.25 | Metaswitzerite | Mn2+3(PO4)2 · 4H2O |
| 8.CE.30 | Pradetite | CoCu4(AsO4)2(HAsO4)2 · 9H2O |
| 8.CE.30 | Veselovskýite | ZnCu4(AsO4)2(HAsO4)2 · 9H2O |
| 8.CE.30 | Lindackerite | CuCu4(AsO4)2(HAsO4)2 · 9H2O |
| 8.CE.30 | Klajite | MnCu4(AsO4)2(HAsO4)2 · 9-10H2O |
| 8.CE.30 | Hloušekite | (Ni,Co)Cu4(AsO4)2(AsO3OH)2 · 9H2O |
| 8.CE.30 | Ondrušite | CaCu4(AsO4)2(HAsO4)2 · 10H2O |
| 8.CE.35 | Bobierrite | Mg3(PO4)2 · 8H2O |
| 8.CE.40 | Barićite | (Mg,Fe)3(PO4)2 · 8H2O |
| 8.CE.40 | Parasymplesite | Fe2+3(AsO4)2 · 8H2O |
| 8.CE.40 | Gritsenkoite | CoMg2(AsO4)2(H2O)8 |
| 8.CE.40 | Cabrerite | NiMg2(AsO4)2 · 8H2O |
| 8.CE.40 | Pakhomovskyite | Co3(PO4)2 · 8H2O |
| 8.CE.40 | Vivianite | Fe2+Fe2+2(PO4)2 · 8H2O |
| 8.CE.40 | Arupite | Ni3(PO4)2 · 8H2O |
| 8.CE.40 | Erythrite | Co3(AsO4)2 · 8H2O |
| 8.CE.40 | Hörnesite | Mg3(AsO4)2 · 8H2O |
| 8.CE.40 | Köttigite | Zn3(AsO4)2 · 8H2O |
| 8.CE.40 | Ferrisymplesite | Fe3+3(AsO4)2(OH)3 · 5H2O |
| 8.CE.40 | Annabergite | Ni3(AsO4)2 · 8H2O |
| 8.CE.45 | Symplesite | Fe2+3(AsO4)2 · 8H2O |
| 8.CE.50 | Cattiite | Mg3(PO4)2 · 22H2O |
| 8.CE.55 | Koninckite | Fe3+PO4 · 3H2O |
| 8.CE.60 | Kaňkite | FeAsO4 · 3.5H2O |
| 8.CE.60 | Hilarionite | Fe3+2(SO4)(AsO4)(OH) · 6H2O |
| 8.CE.65 | Steigerite | Al(VO4) · 3H2O |
| 8.CE.70 | Metaschoderite | Al2(PO4)(VO4) · 6H2O |
| 8.CE.70 | Schoderite | Al2(PO4)(VO4) · 8H2O |
| 8.CE.75 | Zigrasite | MgZr(PO4)2 · 4H2O |
| 8.CE.75 | 'UM2009-11-PO:CaHZr' | CaZr[PO4]2 · 4H2O |
| 8.CE.75 | Malhmoodite | FeZr(PO4)2 · 4H2O |
| 8.CE.80 | Santabarbaraite | Fe3+3(PO4)2(OH)3 · 5H2O |
| 8.CE.85 | Metaköttigite | (Zn,Fe,Fe)3(AsO4)2 · 8(H2O,OH) |
| 8.CE.90 | Slavkovite | Cu13(AsO4)6(AsO3OH)4 · 23H2O |
Fluorescence of Manganohörnesite
Not fluorescent.
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.
Internet Links for Manganohörnesite
mindat.org URL:
https://www.mindat.org/min-2495.html
Please feel free to link to this page.
Please feel free to link to this page.
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External Links:
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References for Manganohörnesite
Reference List:
Localities for Manganohörnesite
Showing 13 localities.
symbol to view information about a locality.
The Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - 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.
Chile | |
| samples analysed by Gerhard Mohn and ... |
Germany | |
| Walenta (2001) |
| Walenta (2001) | |
| Desor (04/2020) |
Slovakia | |
| Martin Števko |
Spain | |
| Rewitzer et al. (2019) |
Sweden (TL) | |
| Gabrielson (1952) +1 other reference |
| Gatedal (n.d.) | |
| RRUFF ID: R061005 | |
| Nysten (2004) |
| Nysten et al. (2016) +1 other reference |
Switzerland | |
| Ansermet (2012) |
USA | |
| Parker (1982) +1 other reference |
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Schmiedestollen dump, Wittichen, Schenkenzell, Rottweil, Freiburg Region, Baden-Württemberg, Germany