Kummerite
A valid IMA mineral species
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About Kummerite
Formula:
Mn2+Fe3+Al(PO4)2(OH)2 · 8H2O
Crystallochemical formula: Mn2+(H2O)4[Fe3+(OH)(PO4)2Al(OH)(H2O)2](H2O)2
Colour:
Amber yellow
Lustre:
Vitreous
Specific Gravity:
2.34 (Calculated)
Crystal System:
Triclinic
Member of:
Name:
Named for Rudolf Kummer (1924-1982), mining director of the Cornelia mine at Hagendorf Süd from 1964 until his death in 1982. Rudi had a great appreciation of, and familiarity with the mineral occurrences at the mine and he was very supportive of geologists, mineralogists and collectors who came to study and collect samples from the mine.
Type Locality:
Isostructural with:
Chemically similar to rittmannite.
A difference from laueite: Al and Fe3+ are ordered into alternate octahedral sites within chains.
A difference from laueite: Al and Fe3+ are ordered into alternate octahedral sites within chains.
Unique Identifiers
Mindat ID:
46707
Long-form identifier:
mindat:1:1:46707:0
Similar Names
| Gumberite | A rock classification type | |
| Hummerite | A valid IMA mineral species - grandfathered | K2Mg2(V10O28) · 16H2O |
| Komarite | A synonym of Willemseite |
Classification of Kummerite
Laueite structure archetype
In kummerite, the M1 site is occupied by Mn2+, the M2 is occupied by Fe3+, and the M3 site is occupied by Al3+. The X site is a phosphate group. Kummerite is unusual in that the other members of the laueite supergroup don't exhibit different site-defining cations between their M2 and M3 sites. This is similar to rittmannite in the jahnsite supergroup.
IMA Classification of Kummerite
Approved
IMA Formula:
Mn2+Fe3+Al(PO4)2(OH)2·8H2O
Approval year:
2015
First published:
2016
8.DC.30
8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
C : With only medium-sized cations, (OH, etc.):RO4 = 1:1 and < 2:1
8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
C : With only medium-sized cations, (OH, etc.):RO4 = 1:1 and < 2:1
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 |
|---|---|---|
| Kum | 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 Kummerite
Vitreous
Transparency:
Translucent
Colour:
Amber yellow
Streak:
White
Tenacity:
Brittle
Cleavage:
Distinct/Good
Parallel to {010}
Parallel to {010}
Fracture:
Irregular/Uneven
Density:
2.34 g/cm3 (Calculated)
Optical Data of Kummerite
Type:
Biaxial (-)
RI values:
nα = 1.565(5) nβ = 1.600(5) nγ = 1.630(5)
2V:
Calculated: 84°
Max. Birefringence:
δ = 0.065
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:
weak
Pleochroism:
Weak
Comments:
amber yellow
Chemistry of Kummerite
Mindat Formula:
Mn2+Fe3+Al(PO4)2(OH)2 · 8H2O
Crystallochemical formula: Mn2+(H2O)4[Fe3+(OH)(PO4)2Al(OH)(H2O)2](H2O)2
Crystallochemical formula: Mn2+(H2O)4[Fe3+(OH)(PO4)2Al(OH)(H2O)2](H2O)2
Element Weights:
Common Impurities:
Mg,Fe(II),(Zn)
Crystallography of Kummerite
Crystal System:
Triclinic
Class (H-M):
1 - Pinacoidal
Space Group:
P1
Cell Parameters:
a = 5.320(1) Å, b = 10.670(3) Å, c = 7.139(1) Å
β = 111.40(3)°, γ = 71.84(2)°
β = 111.40(3)°, γ = 71.84(2)°
Ratio:
a:b:c = 0.499 : 1 : 0.669
Unit Cell V:
nan ų (Calculated from Unit Cell)
Z:
1
Morphology:
Very thin, often deformed laths forming aggregates (spray, rounded)
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 9.885 Å | (100) |
| 6.476 Å | (20) |
| 4.942 Å | (30) |
| 3.988 Å | (9) |
| 3.255 Å | (8) |
| 3.235 Å | (9) |
| 3.116 Å | (18) |
| 2.873 Å | (11) |
Comments:
From Type Description.
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| 47c : [Carbonates, phosphates, borates, nitrates] | |
| 47e : [Vanadates, chromates, manganates] |
Type Occurrence of Kummerite
General Appearance of Type Material:
Aggregates are commonly 100 to 500 µm in their longest dimension, but the individual lamellae, parallel to {010} have a thickness of the order of a few µm
Place of Conservation of Type Material:
Type material is deposited in the mineralogical collections of the Museum Victoria, Melbourne, Victoria, Australia, registration number M53448
Geological Setting of Type Material:
Pegmatite
Associated Minerals at Type Locality:
Synonyms of Kummerite
Other Language Names for Kummerite
Relationship of Kummerite to other Species
Member of:
Other Members of Laueite Group:
| Ferrolaueite | Fe2+Fe3+2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
| Gordonite | MgAl2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
| Kastningite | (Mn2+,Fe2+,Mg)Al2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
| Laueite | Mn2+Fe3+2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
| Mangangordonite | Mn2+Al2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
| Paravauxite | Fe2+Al2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
| Sigloite | Fe3+Al2(PO4)2(OH)3 · 7H2O | Tric. 1 : P1 |
| Stewartite | Mn2+Fe3+2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
| Ushkovite | MgFe3+2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
Common Associates
Associations Based on Photo Data:
| 4 photos of Kummerite associated with Ferroberaunite | Fe2+Fe3+5(PO4)4(OH)5 · 6H2O |
| 3 photos of Kummerite associated with Stewartite | Mn2+Fe3+2(PO4)2(OH)2 · 8H2O |
Related Minerals - Strunz-mindat Grouping
| 8.DC. | Ferroberaunite | Fe2+Fe3+5(PO4)4(OH)5 · 6H2O |
| 8.DC. | Césarferreiraite | Fe2+ Fe3+2(AsO4)2(OH)2 · 8H2O |
| 8.DC. | Ferrivauxite | Fe3+Al2(PO4)2(OH)3 · 5H2O |
| 8.DC. | Ianbruceite | Zn2(AsO4)(OH) · 3H2O |
| 8.DC.05 | Nissonite | Cu2Mg2(PO4)2(OH)2 · 5H2O |
| 8.DC.07 | Euchroite | Cu2(AsO4)(OH) · 3H2O |
| 8.DC.10 | Legrandite | Zn2(AsO4)(OH) · H2O |
| 8.DC.12 | Strashimirite | Cu8(AsO4)4(OH)4 · 5H2O |
| 8.DC.15 | Earlshannonite | Mn2+Fe3+2(PO4)2(OH)2 · 4H2O |
| 8.DC.15 | Kunatite | CuFe3+2(PO4)2(OH)2 · 4H2O |
| 8.DC.15 | 'UM2006-27-PO:FeHZn' | ZnFe3+2(PO4)2(OH)2 · 4H2O |
| 8.DC.15 | 'UKI-2006-(PO:AlCuFeH)' | Fe2+Al3+2(PO4)2(OH)2 · 4H2O |
| 8.DC.15 | Cobaltarthurite | CoFe3+2(AsO4)2(OH)2 · 4H2O |
| 8.DC.15 | Arthurite | CuFe3+2(AsO4)2(OH)2 · 4H2O |
| 8.DC.15 | Ojuelaite | ZnFe3+2(AsO4)2(OH)2 · 4H2O |
| 8.DC.15 | Whitmoreite | Fe2+Fe3+2(PO4)2(OH)2 · 4H2O |
| 8.DC.15 | Bendadaite | Fe2+Fe3+2(AsO4)2(OH)2 · 4H2O |
| 8.DC.17 | Kleemanite | ZnAl2(PO4)2(OH)2 · 3H2O |
| 8.DC.20 | Magnesiobermanite | MgMn3+2(PO4)2(OH)2 · 4H2O |
| 8.DC.20 | Bermanite | Mn2+Mn3+2(PO4)2(OH)2 · 4H2O |
| 8.DC.20 | Coralloite | Mn2+Mn3+2(AsO4)2(OH)2 · 4H2O |
| 8.DC.22 | Kovdorskite | Mg2(PO4)(OH) · 3H2O |
| 8.DC.25 | Zincostrunzite | ZnFe3+2(PO4)2(OH)2 · 6.5H2O |
| 8.DC.25 | Metavauxite | Fe2+Al2(PO4)2(OH)2 · 8H2O |
| 8.DC.25 | Metavivianite | Fe2+Fe3+2(PO4)2(OH)2 · 6H2O |
| 8.DC.25 | Ferristrunzite | Fe3+Fe3+2(PO4)2(OH)3 · 5H2O |
| 8.DC.25 | Strunzite | Mn2+Fe3+2(PO4)2(OH)2 · 6H2O |
| 8.DC.25 | Ferrostrunzite | Fe2+Fe3+2(PO4)2(OH)2 · 6H2O |
| 8.DC.27 | Beraunite | Fe3+6(PO4)4O(OH)4 · 6H2O |
| 8.DC.27 | Tvrdýite | Fe2+Fe3+2Al3(PO4)4(OH)5(H2O)4 · 2H2O |
| 8.DC.27 | Zincoberaunite | ZnFe3+5(PO4)4(OH)5 · 6H2O |
| 8.DC.30 | Maghrebite | MgAl2(AsO4)2(OH)2 · 8H2O |
| 8.DC.30 | Ferrolaueite | Fe2+Fe3+2(PO4)2(OH)2 · 8H2O |
| 8.DC.30 | Ushkovite | MgFe3+2(PO4)2(OH)2 · 8H2O |
| 8.DC.30 | Laueite | Mn2+Fe3+2(PO4)2(OH)2 · 8H2O |
| 8.DC.30 | Paravauxite | Fe2+Al2(PO4)2(OH)2 · 8H2O |
| 8.DC.30 | Sigloite | Fe3+Al2(PO4)2(OH)3 · 7H2O |
| 8.DC.30 | Nordgauite | MnAl2(PO4)2(F,OH)2 · 5H2O |
| 8.DC.30 | Kayrobertsonite | [MnAl2(PO4)2(OH)2(H2O)4] · 2H2O |
| 8.DC.30 | Mangangordonite | Mn2+Al2(PO4)2(OH)2 · 8H2O |
| 8.DC.30 | Stewartite | Mn2+Fe3+2(PO4)2(OH)2 · 8H2O |
| 8.DC.30 | Gordonite | MgAl2(PO4)2(OH)2 · 8H2O |
| 8.DC.30 | Kastningite | (Mn2+,Fe2+,Mg)Al2(PO4)2(OH)2 · 8H2O |
| 8.DC.30 | Pseudolaueite | Mn2+Fe3+2(PO4)2(OH)2 · 8H2O |
| 8.DC.32 | Kamarizaite | Fe3+3(AsO4)2(OH)3 · 3H2O |
| 8.DC.32 | Tinticite | Fe3+3(PO4)2(OH)3 · 3H2O |
| 8.DC.35 | Vauxite | Fe2+Al2(PO4)2(OH)2 · 6H2O |
| 8.DC.37 | Vantasselite | Al4(PO4)3(OH)3 · 9H2O |
| 8.DC.40 | Cacoxenite | Fe3+24AlO6(PO4)17(OH)12 · 75H2O |
| 8.DC.45 | Souzalite | Mg3Al4(PO4)4(OH)6 · 2H2O |
| 8.DC.45 | Gormanite | (Fe2+,Mg)3(Al,Fe3+)4(PO4)4(OH)6 · 2H2O |
| 8.DC.47 | Kingite | Al3(PO4)2F2(OH) · 7H2O |
| 8.DC.50 | Allanpringite | Fe3+3(PO4)2(OH)3 · 5H2O |
| 8.DC.50 | Fluorwavellite | Al3(PO4)2(OH)2F · 5H2O |
| 8.DC.50 | Wavellite | Al3(PO4)2(OH)3 · 5H2O |
| 8.DC.52 | Kribergite | Al5(PO4)3(SO4)(OH)4 · 4H2O |
| 8.DC.55 | Mapimite | Zn2Fe3+3(AsO4)3(OH)4 · 10H2O |
| 8.DC.57 | Ogdensburgite | Ca2Fe3+4(Zn,Mn2+)(AsO4)4(OH)6 · 6H2O |
| 8.DC.60 | Cloncurryite | Cu0.5(VO)0.5Al2(PO4)2F2 · 5H2O |
| 8.DC.60 | Nevadaite | (Cu2+,Al,V3+)6Al8(PO4)8F8(OH)2 · 22H2O |
| 8.DC.62 | Kenngottite | Mn2+3Fe3+4(PO4)4(OH)6(H2O)2 |
| 8.DC.67 | Molinelloite | Cu(H2O)(OH)V4+O(V5+O4) |
| 8.DC.70 | Whitecapsite | H16Fe2+5Fe3+14Sb3+6(AsO4)18O16 · 120H2O |
| 8.DC.75 | Heimite | PbCu2(AsO4)(OH)3 · 2H2O |
| 8.DC.80 | Lednevite | Cu[PO3(OH)] · H2O |
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 Kummerite
mindat.org URL:
https://www.mindat.org/min-46707.html
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References for Kummerite
Reference List:
Hålenius, U., Hatert, F., Pasero, M., Mills, S. J. (2015) New minerals and nomenclature modifications approved in 2015, CNMNC Newsletter 26. Mineralogical Magazine, 79 (4) 941-947 doi:10.1180/minmag.2015.079.4.05
Grey, I. E., Keck, E., Mumme, W. G., Pring, A., Macrae, C. M., Glenn, A. M., Davidson, C. J., Shanks, F. L., Mills, S. J. (2016) Kummerite, Mn2+Fe3+Al(PO4)2(OH)2·8H2O, a new laueite-group mineral from the Hagendorf Süd pegmatite, Bavaria, with ordering of Al and Fe3+. Mineralogical Magazine, 80 (7) 1243-1254 doi:10.1180/minmag.2016.080.061
Localities for Kummerite
Showing 2 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.
Brazil | |
| Sergio Varvello collection |
Germany (TL) | |
| Hålenius et al. (2015) +1 other reference |
Quick NavTopAbout KummeriteUnique IdentifiersSimilar NamesClassification IMA Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography X-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesRelationshipsCommon AssociatesStrunz-MindatOther InformationInternet Links References Localities Locality List
Hagendorf South Pegmatite, Hagendorf, Waidhaus, Neustadt an der Waldnaab District, Upper Palatinate, Bavaria, Germany