Ramsdellite
A valid IMA mineral species - grandfathered
This page is currently not sponsored. Click here to sponsor this page.
About Ramsdellite
Lewis S. Ramsdell
Formula:
Mn4+O2
Colour:
Black, steel-grey
Lustre:
Sub-Metallic
Hardness:
3
Specific Gravity:
4.37
Crystal System:
Orthorhombic
Member of:
Name:
Named in honor of Lewis Stephen Ramsdell (4 June 1895, Clinton, Michigan, USA - 14 July 1975, Palo Alto, California, USA), Professor of Mineralogy at the University of Michigan, who first described the mineral.
Type Locality:
Polymorph of:
Forms by inversion of pyrolusite or oxidative dehydrogenation of groutite.
The "groutellite" variety is sometimes (e.g., Bernardini et al., 2020) given as [(Mn4+0.5,Mn3+0.5)O1.5(OH)0.5].
Well-recognizable via vibrational (Raman) spectroscopy.
Laser-induced degradation of "groutellite" gives "true" ramsdellite, via the loss of H+ and oxidation of Mn(III) to Mn(IV), "already at a very low laser power". With further increase of the laser power hausmannite is formed due to reduction of Mn. Final product is groutite. These observations relate to discharge mechanism in cathodic battery materials.
The "groutellite" variety is sometimes (e.g., Bernardini et al., 2020) given as [(Mn4+0.5,Mn3+0.5)O1.5(OH)0.5].
Well-recognizable via vibrational (Raman) spectroscopy.
Laser-induced degradation of "groutellite" gives "true" ramsdellite, via the loss of H+ and oxidation of Mn(III) to Mn(IV), "already at a very low laser power". With further increase of the laser power hausmannite is formed due to reduction of Mn. Final product is groutite. These observations relate to discharge mechanism in cathodic battery materials.
Unique Identifiers
Mindat ID:
3359
Long-form identifier:
mindat:1:1:3359:2
IMA Classification of Ramsdellite
Approved, 'Grandfathered' (first described prior to 1959)
Classification of Ramsdellite
4.DB.15a
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
D : Metal: Oxygen = 1:2 and similar
B : With medium-sized cations; chains of edge-sharing octahedra
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
D : Metal: Oxygen = 1:2 and similar
B : With medium-sized cations; chains of edge-sharing octahedra
Dana 7th ed.:
4.4.7.1
4.4.7.1
4 : SIMPLE OXIDES
4 : AX2
4 : SIMPLE OXIDES
4 : AX2
7.18.4
7 : Oxides and Hydroxides
18 : Oxides of Mn
7 : Oxides and Hydroxides
18 : Oxides 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.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Rmd | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
| Rmd | The Canadian Mineralogist (2019) | The Canadian Mineralogist (2019) The Canadian Mineralogist list of symbols for rock- and ore-forming minerals (December 30, 2019). download |
Physical Properties of Ramsdellite
Sub-Metallic
Transparency:
Opaque
Colour:
Black, steel-grey
Streak:
Brownish black, black
Hardness:
3 on Mohs scale
Cleavage:
Distinct/Good
Density:
4.37 g/cm3 (Measured) 4.79 g/cm3 (Calculated)
Optical Data of Ramsdellite
Anisotropism:
Strong; pale yellow.
Bireflectance:
Distinct.
Colour in reflected light:
Yellowish white.
Comments:
No published reflectivity data.
Chemistry of Ramsdellite
Mindat Formula:
Mn4+O2
Elements listed:
Crystallography of Ramsdellite
Crystal System:
Orthorhombic
Class (H-M):
mmm(2/m2/m2/m) - Dipyramidal
Cell Parameters:
a = 4.53 Å, b = 9.27 Å, c = 2.86 Å
Ratio:
a:b:c = 0.489 : 1 : 0.309
Unit Cell V:
120.43 ų
Z:
4
Comment:
Non-standard space-group setting Pbnm.
Crystal Structure
Load
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Show
Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
Display Options
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
View
CIF File Best | x | y | z | a | b | c
CIF File Best | x | y | z | a | b | c
Rotation
Stop | Start
Stop | Start
Labels
Console Off | On | Grey | Yellow
Console Off | On | Grey | Yellow
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) |
|---|---|---|---|---|---|---|---|
| 0003565 | Ramsdellite | Post J E, Heaney P J (2004) Neutron and synchrotron X-ray diffraction study of the structures and dehydration behaviors of ramsdellite and "groutellite" American Mineralogist 89 969-975 |  | 2004 | 0 | 293 | |
| 0017793 | Ramsdellite | Kondrashev Y D, Zaslavskii A I (1951) The structure of the modifications of manganese oxide Izvestiya Akademii Nauk SSSR 15 179-186 | 1951 | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Loading XRD data...
Data courtesy of RRUFF project at University of Arizona, used with permission.
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 4.08 Å | (10) |
| 2.53 Å | (8) |
| 2.13 Å | (5) |
| 1.88 Å | (5) |
| 1.64 Å | (6) |
| 1.60 Å | (7) |
| 1.46 Å | (5) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Near-surface Processes | |
| 25 : Evaporites (prebiotic) | |
| 28 : Photo-alteration, pre-biotic | |
| Stage 7: Great Oxidation Event | <2.4 |
| 47e : [Vanadates, chromates, manganates] | |
| 47h : [Near-surface oxidized, dehydrated minerals] |
Geological Setting:
No designated type material.
Type Occurrence of Ramsdellite
Synonyms of Ramsdellite
Other Language Names for Ramsdellite
Relationship of Ramsdellite to other Species
Member of:
Other Members of Ramsdellite Group:
| Akhtenskite | ε-Mn4+O2 | Hex. 6/mmm(6/m2/m2/m) : P63/mmc |
| Nsutite | (Mn4+,Mn2+)(O,OH)2 | Hex. |
| Paramontroseite | V4+O2 | Orth. mmm(2/m2/m2/m) |
Common Associates
Associations Based on Photo Data:
| 20 photos of Ramsdellite associated with Pyrolusite | Mn4+O2 |
| 15 photos of Ramsdellite associated with Nsutite | (Mn4+,Mn2+)(O,OH)2 |
| 11 photos of Ramsdellite associated with Todorokite | (Na,Ca,K,Ba,Sr)1-x(Mn,Mg,Al)6O12 · 3-4H2O |
| 10 photos of Ramsdellite associated with Calcite | CaCO3 |
| 9 photos of Ramsdellite associated with Quartz | SiO2 |
| 6 photos of Ramsdellite associated with Hematite | Fe2O3 |
| 4 photos of Ramsdellite associated with Groutite | Mn3+O(OH) |
| 4 photos of Ramsdellite associated with 'Petrified Wood' | |
| 4 photos of Ramsdellite associated with 'Amethyst' | SiO2 |
| 3 photos of Ramsdellite associated with Goethite | Fe3+O(OH) |
Related Minerals - Strunz-mindat Grouping
| 4.DB. | Tianhongqiite | CrTiO3(OH) |
| 4.DB. | Nioboheftetjernite | ScNbO4 |
| 4.DB. | Huangshanite | Fe3+TaO4 |
| 4.DB. | Nioboixiolite-(Mn2+) | (Nb0.67Mn2+0.33)O2 |
| 4.DB. | Shakhdaraite-(Y) | ScYNb2O8 |
| 4.DB.05 | Varlamoffite | Sn1-xFexO2-x(OH) |
| 4.DB.05 | Argutite | GeO2 |
| 4.DB.05 | Cassiterite | SnO2 |
| 4.DB.05 | Rutile | TiO2 |
| 4.DB.05 | Plattnerite | PbO2 |
| 4.DB.05 | Tripuhyite | Fe3+Sb5+O4 |
| 4.DB.05 | Tugarinovite | MoO2 |
| 4.DB.05 | Pyrolusite | Mn4+O2 |
| 4.DB.10 | Byströmite | MgSb2O6 |
| 4.DB.10 | Ordoñezite | ZnSb2O6 |
| 4.DB.10 | Tredouxite | NiSb2O6 |
| 4.DB.10 | Tapiolite-(Mn) | Mn2+Ta2O6 |
| 4.DB.10 | Tapiolite-(Fe) | Fe2+Ta2O6 |
| 4.DB.15a | Paramontroseite | V4+O2 |
| 4.DB.15b | Akhtenskite | ε-Mn4+O2 |
| 4.DB.15c | Nsutite | (Mn4+,Mn2+)(O,OH)2 |
| 4.DB.20 | Scrutinyite | α-PbO2 |
| 4.DB.20 | Nioboixiolite-([]) | (Nb0.8◻0.2)4+O2 |
| 4.DB.25 | Ishikawaite | U4+Fe2+Nb2O8 |
| 4.DB.25 | Yttrocolumbite-(Y) | Y(U4+,Fe2+)Nb2O8 |
| 4.DB.25 | Calciosamarskite | (Ca,U4+)Fe3+(Nb,Ta,Ti)2O8 |
| 4.DB.25 | Samarskite-(Yb) | YbFe3+(Nb,Ta)2O8 |
| 4.DB.25 | Ixiolite-(Sc) | (Ta0.5Sc0.5)O2 |
| 4.DB.25 | Ixiolite-(Fe2+) | (Ta0.67Fe2+0.33)O2 |
| 4.DB.25 | Ixiolite-(Mn2+) | (Ta0.67Mn2+0.33)O2 |
| 4.DB.25 | Nioboixiolite-(Fe2+) | (Nb0.67Fe2+0.33)O2 |
| 4.DB.25 | Srilankite | TiO2 |
| 4.DB.25 | Samarskite-(Y) | YFe3+Nb2O8 |
| 4.DB.25 | Nioboixiolite-(Fe3+) | (Nb0.5Fe3+0.5)O2 |
| 4.DB.30 va | Wolframite Group | |
| 4.DB.30 | Rossovskyite | (Fe3+,Ta)(Nb,Ti)O4 |
| 4.DB.30 | Huanzalaite | MgWO4 |
| 4.DB.30 | Heftetjernite | ScTaO4 |
| 4.DB.30 | Hübnerite | MnWO4 |
| 4.DB.30 | Sanmartinite | (Zn,Fe)WO4 |
| 4.DB.30 | Ferberite | FeWO4 |
| 4.DB.30 | 'Krasnoselskite' | CoWO4 |
| 4.DB.35 | Qitianlingite | (Fe,Mn)2(Nb,Ta)2WO10 |
| 4.DB.35 | Tantalaeschynite-(Ce) | Ce(TiTa)O6 |
| 4.DB.35 | Tantalite-(Mg) | (Mg,Fe2+)(Ta,Nb)2O6 |
| 4.DB.35 | Columbite-(Mn) | Mn2+Nb2O6 |
| 4.DB.35 | Tantalite-(Mn) | Mn2+Ta2O6 |
| 4.DB.35 | Columbite-(Fe) | Fe2+Nb2O6 |
| 4.DB.35 | Columbite-(Mg) | (Mg,Fe,Mn)(Nb,Ta)2O6 |
| 4.DB.35 | Tantalite-(Fe) | Fe2+Ta2O6 |
| 4.DB.40 | Ferrotitanowodginite | Fe2+TiTa2O8 |
| 4.DB.40 | 'Wolframowodginite' | Mn(Mn,Sn,Fe,Ta)(W,Ta,Nb)2O8 |
| 4.DB.40 | Lithiotantite | LiTa3O8 |
| 4.DB.40 | Lithiowodginite | LiTa3O8 |
| 4.DB.40 | Titanowodginite | Mn2+TiTa2O8 |
| 4.DB.40 | Tantalowodginite | (Mn2+0.5◻0.5)TaTa2O8 |
| 4.DB.40 | Wodginite | Mn2+Sn4+Ta2O8 |
| 4.DB.40 | Ferrowodginite | Fe2+Sn4+Ta2O8 |
| 4.DB.45 | Tivanite | V3+TiO3(OH) |
| 4.DB.50 | Carmichaelite | (Ti,Cr,Fe)[O2-x(OH)x] |
| 4.DB.55 | Alumotantite | AlTaO4 |
| 4.DB.60 | Biehlite | ((Sb,As)O)2[MoO4] |
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 Ramsdellite
mindat.org URL:
https://www.mindat.org/min-3359.html
Please feel free to link to this page.
Please feel free to link to this page.
Search Engines:
External Links:
Mineral Dealers:
References for Ramsdellite
Reference List:
Ramsdell, Lewis S. (1932) An X-ray study of psilomelane and wad. American Mineralogist, 17 (4) 143-149
Fleischer, Michael, Richmond, Wallace Everett (1943) The manganese oxide minerals, a preliminary report. Economic Geology, 38 (4) 269-286 doi:10.2113/gsecongeo.38.4.269
Byström, Ann Marie, Lund, E. Wang, Lund, L. Koren, Hakala, Maire (1949) The Crystal Structure of Ramsdellite, an Orthorhombic Modification of MnO2. Acta Chemica Scandinavica, 3. 163-173 doi:10.3891/acta.chem.scand.03-0163
Klingsberg, Cyrus, Roy, Rustum (1957) Ramsdellite: newly observed in Minnesota. Economic Geology, 52 (5) 574-577 doi:10.2113/gsecongeo.52.5.574
Mukherjee, Bibhuti (1959) An X-ray study of manganese minerals. Mineralogical Magazine and Journal of the Mineralogical Society, 32 (247) 332-339 doi:10.1180/minmag.1959.032.247.06
Fleischer, Michael, Richmond, W. E., Evans, Howard T. (1962) Studies of the manganese oxides. V. Ramsdellite, MnO2, an orthorhombic dimorph of pyrolusite. American Mineralogist, 47 (1-2) 47-58
Majmundar, H. H. (1969) Ramsdellite and groutite from Nova Scotia. The Canadian Mineralogist, 9 (5) 718-720
Potter, Russell M., Rossman, George R (1979) The tetravalent manganese oxides: identification, hydration, and structural relationships by infrared spectroscopy. American Mineralogist, 64 (11-12) 1199-1218
Miura, Hiroyuki, Kudou, Haruhiko, Choi, Jai Ho, Hariya, Yu (1990) The Crystal Structure of Ramsdellite from Pirika Mine. Journal of the Faculty of Science, Hokkaido University. Series 4, Geology and mineralogy, 22 (4). 611-617
Fong, C., Kennedy, B. J., Elcombe, M. M. (1994) A powder neutron diffraction study of λ and γ manganese dioxide and of LiMn2O4. Zeitschrift für Kristallographie - Crystalline Materials, 209 (12) 941-945 doi:10.1524/zkri.1994.209.12.941
Kohler, Thomas, Armbruster, Thomas, Libowitzky, Eugen (1997) Hydrogen Bonding and Jahn–Teller Distortion in Groutite,α-MnOOH, and Manganite,γ-MnOOH, and Their Relations to the Manganese Dioxides Ramsdellite and Pyrolusite. Journal of Solid State Chemistry, 133. 486-500 doi:10.1006/jssc.1997.7516
Localities for Ramsdellite
Showing 125 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.
Argentina | |
| ... |
| Trueman et al. (2020) |
Australia | |
| Worner et al. (1982) |
| |
Azerbaijan | |
| Pavel M. Kartashov (n.d.) |
Brazil | |
| Dr. Günter Grundmann collection |
Bulgaria | |
| I. Kostov et al. (1964) |
Burkina Faso | |
| Hénocque et al. (1998) |
Canada | |
| Boyle (1972) |
| Majmundar (1969) |
| Fleischer et al. (1962) |
Chile | |
| Maurizio Dini - analysed material by ... |
China | |
| |
Czech Republic | |
| Bufka |
Finland | |
| Ilkka Mikkola collection EDS+XRD ... |
France | |
| Wittern et al. (1997) |
| Perseil (1975) | |
| Perseil (1975) | |
| Wittern et al. (1997) |
| Berger et al. (2011) +1 other reference |
| Patureau et al. (2011) |
| Perseil (1967) |
| De Ascenção Guedes et al. (2002) |
| De Ascenção Guedes et al. (2002) |
| Georges FAVREAU collection + EDX ... |
| Melle André & Meisser Nicolas +1 other reference | |
Gabon | |
| Lheur (2001) +1 other reference |
Germany | |
| Walenta (1989) +1 other reference |
| Walenta (1992) |
| Weiß (1990) |
| Belendorff (2007) |
| Petitjean et al. (2007) |
| Schnorrer et al. (2002) +1 other reference |
| Weiß (1990) |
| Johannes Markus Henrich +2 other references |
| Th.Lühr collection |
| Wittern (2001) |
Ghana | |
| Mücke et al. (1999) |
Greece | |
| |
| Hanke (1996) |
| Hein +11 other references |
Hungary | |
| Koch (1985) |
| GEODA |
| Szakáll & Jánosi (1996) |
| Szakáll & Gatter |
India | |
| Sivaprakash (1980) |
| Sivaprakash (1980) | |
| Sivaprakash (1981) | |
| Rao et al. (1979) |
| Mallick et al. (2005, March) |
| Rao +1 other reference |
Iran | |
| Rajabi et al. (2025) |
| Rajabi et al. (2025) |
| Rajabi et al. (2025) | |
| Shahin et al. (2023) |
Italy | |
| Palenzona A. (1991) |
| Vergani et al. (2021) |
| Matteo Giai et al. (2023) +1 other reference |
| Parola et al. (2023) +1 other reference |
| Fernando Caboni et al. (2024) |
| Fernando Caboni et al. (2024) | |
| Probed by Prof. Giuseppetti +1 other reference |
| Boscardin et al. (2011) |
Japan | |
| - (n.d.) |
| Miura +4 other references |
| Nambu et al. (1961) |
| Watanabe (1959) |
| University of Tokyo collection |
| Petrov (n.d.) |
Luxembourg | |
| MnhnL collection |
Mexico | |
| Panczner (1987) |
| [MinRec 14:110 | |
| Panzcer (1987) | |
| Panzcer | |
| Panczner (1987) |
| Finkelman et al. (1974) |
| Cross (2006) |
| Megaw (1990) |
| King (1981) |
| Panczner (1987) | |
Norway | |
| Breivik (2018) |
| Neumann (1985) +1 other reference |
| Neumann (1959) |
| Rune S. Selbekk (2010) |
Portugal | |
| Alves (n.d.) |
| e-rocks.com (n.d.) |
| Schnorrer-Köhler et al. (1991) |
| Martins da Pedra collection |
Romania | |
| minerals-of-the-carpathians.eu (2008) |
| Hîrtopanu (1997) +1 other reference |
Russia | |
| Kasatkin et al. (2021) |
Slovakia | |
| Majzlan et al. (2025) |
| Majzlan et al. (2025) | |
| Majzlan et al. (2025) | |
South Africa | |
| Gutzmer (1996) |
| Wilson et al. (1978) +1 other reference |
| Cairncross et al. (1995) | |
Spain | |
| Georges FAVREAU collection & EDX ... |
| Dill et al. (2023) |
Sweden | |
| Gatedal (n.d.) |
Switzerland | |
| Ansermet (2012) |
Turkey | |
| Oksuz (2018) |
UK | |
| T.F. Cotterell +1 other reference |
| Cotterell (2009) |
USA | |
| Hewett (1964) +1 other reference |
| Mouat (1962) +1 other reference |
| Anthony et al. (1995) +1 other reference |
| Anthony et al. (1995) | |
| Mouat (1962) +1 other reference | |
| Bideaux et al. (1960) +2 other references |
| Thomssen (1983) +1 other reference | |
| Bideaux et al. (1960) +2 other references | |
| Bideaux (1980) +1 other reference |
| Wilkinson et al. (1983) +1 other reference |
| Anthony et al. (1995) |
| Hadley (1942) +4 other references |
| Rocks & Minerals (July-August, 2002) |
| Klingsberg et al. (1957) +1 other reference |
| Prinz (1967) +1 other reference |
| Guilbert et al. (1964) +1 other reference |
| Northrop et al. (1996) |
| Northrop et al. (1996) |
| Northrop et al. (1996) | |
| Northrop et al. (1996) |
| Van Rythoven et al. (2020) |
Quick NavTopAbout RamsdelliteUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography Crystal StructureX-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesRelationshipsCommon AssociatesStrunz-MindatOther InformationInternet Links References Localities Locality List
Mistake Mine, Box Canyon Mining District, Yavapai County, Arizona, USA