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Pyrolusite

A valid IMA mineral species - grandfathered
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About PyrolusiteHide

Formula:
Mn4+O2
Colour:
Black or very dark grey.
Lustre:
Metallic, Dull, Earthy
Hardness:
2 - 6½
Specific Gravity:
5.04 - 5.08
Crystal System:
Tetragonal
Member of:
Name:
Named in 1827 from the Greek for "fire" and "to wash," because it was used to remove brown and green tints in the making of glass.
Polymorph of:
Rutile Group.

Usually found as matte-black powdery to fibrous crusts, sometimes in botryoidal aggregates or columnar, more rarely as druzes of small prismatic to tabular, dark grey metallic crystals.
May be confused with some manganese oxides, such as todorokite (fibrous variants) and manganite (tabular crystals).

Note: No valid pyrolusite dendrites are known. Supposed specimens of pyrolusite in dendritic form turn out to be other Mn-oxide species (e.g., minerals of the cryptomelane group, birnessite, nsutite, todorokite, etc.) upon being examined in the proper laboratory setting for characterizing these difficult to identify minerals.


Unique IdentifiersHide

Mindat ID:
3318
Long-form identifier:
mindat:1:1:3318:9

IMA Classification of PyrolusiteHide

Approved, 'Grandfathered' (first described prior to 1959)

Classification of PyrolusiteHide

4.DB.05

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.:
4.4.1.4
4.4.1.4

4 : SIMPLE OXIDES
4 : AX2
7.18.3

7 : Oxides and Hydroxides
18 : Oxides of Mn

Mineral SymbolsHide

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.

SymbolSourceReference for Standard
PylIMA–CNMNCWarr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43
PylThe Canadian Mineralogist (2019)The Canadian Mineralogist (2019) The Canadian Mineralogist list of symbols for rock- and ore-forming minerals (December 30, 2019). download
PylWarr (2020)Warr, L.N. (2020) Recommended abbreviations for the names of clay minerals and associated phases. Clay Minerals, 55, 261–264 doi:10.1180/clm.2020.30

Pronunciation of PyrolusiteHide

Pronunciation:
PlayRecorded byCountry
Jolyon RalphUnited Kingdom

Physical Properties of PyrolusiteHide

Metallic, Dull, Earthy
Transparency:
Opaque
Colour:
Black or very dark grey.
Streak:
Black to bluish-black.
Hardness:
2 - 6½ on Mohs scale
Hardness Data:
Measured
Comment:
6 to 6.5 when crystalline, 2 when massive.
Tenacity:
Brittle
Cleavage:
Perfect
Perfect on {110}.
Fracture:
Irregular/Uneven
Density:
5.04 - 5.08 g/cm3 (Measured)    5.189 g/cm3 (Calculated)

Optical Data of PyrolusiteHide

Anisotropism:
Strong, in yellows
Reflectivity:
WavelengthR1 (%)R2 (%)
400nm18.4%29.4%
420nm18.6%30.0%
440nm18.8%30.6%
460nm18.9%31.2%
480nm19.0%31.6%
500nm19.0%31.7%
520nm18.9%31.6%
540nm18.8%31.4%
560nm18.6%31.2%
580nm18.5%30.8%
600nm18.4%30.4%
620nm18.3%30.0%
640nm18.2%29.5%
660nm18.2%28.9%
680nm18.1%28.4%
700nm18.1%28.0%


Graph shows reflectance levels at different wavelengths (in nm). Peak reflectance is 31.7%.
R1 shown in black, R2 shown in red
Colour in reflected light:
Cream-white
Pleochroism:
Weak
Comments:
Very weak. Yellow to yellow-gray.

Chemistry of PyrolusiteHide

Mindat Formula:
Mn4+O2
Element Weights:
Element% weight
Mn63.193 %
O36.807 %

Calculated from ideal end-member formula.

Crystallography of PyrolusiteHide

Crystal System:
Tetragonal
Class (H-M):
4/mmm(4/m2/m2/m) - Ditetragonal Dipyramidal
Space Group:
P42/mnm
Cell Parameters:
a = 4.4041(1) Å, c = 2.8765(1) Å
Ratio:
a:c = 1 : 0.653
Unit Cell V:
55.79 ų (Calculated from Unit Cell)
Z:
2
Morphology:
Crystals are uncommon, either long or short prismatic parallel to [001] or equant; more typically found as earthy powder or fibrous aggregates as crusts on rocks; sometimes as botryoidal aggregates, more rarely as druses of microscopic crystals.
Never found as dendrites despite old literature. [The obsolete term "polianite" was once used to refer to crystalline pyrolusite, which was assumed to be a different species than earthy to crusty pyrolusite.]
Twinning:
Twinning rare. Repeated twins with twin planes {031} and {032}. Polysynthetic twinning observed in polished sections.

Crystal StructureHide

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IDSpeciesReferenceLinkYearLocalityPressure (GPa)Temp (K)
0011760PyrolusiteWyckoff R W G (1963) Second edition. Interscience Publishers, New York, New York Crystal Structures 1 239-44419630293
0017791PyrolusiteKondrashev Y D, Zaslavskii A I (1951) The structure of the modifications of manganese oxide Izvestiya Akademii Nauk SSSR 15 179-18619510293
CIF Raw Data - click here to close

X-Ray Powder DiffractionHide

Loading XRD data...
Data Set:
Data courtesy of RRUFF project at University of Arizona, used with permission.
Powder Diffraction Data:
d-spacingIntensity
3.11 Å(100)
2.41 Å(60)
2.11 Å(20)
1.62 Å(60)
1.56 Å(10)
1.306 Å(20)
1.304 Å(20)
1.000 Å(10)
Comments:
Data given are for synthetic material.

Geological EnvironmentHide

Paragenetic Mode(s):
Geological Setting:
A common Mn mineral, although difficult to distinguish from similar Mn minerals, pyrolusite forms under oxidizing conditions and high pH. Mainly a mineral of lacustrine, shallow marine, and bog deposits, it is also found in the oxidized zones of manganiferous ore deposits and as deposits formed by circulating meteoric water. Both colloidal processes and bacterial action are important in its formation.

Synonyms of PyrolusiteHide

Other Language Names for PyrolusiteHide

Varieties of PyrolusiteHide

PolianiteTerm used to describe Pyrolusite pseudomorphs after "pseudo-orthorombic" Manganite crystals (actual Manganite has a monoclinic structure).
Silver-bearing PyrolusiteApparently a silver-bearing variety of pyrolusite. Seems highly doubtful, probably a mixture.

Relationship of Pyrolusite to other SpeciesHide

Member of:
Other Members of Rutile Group:
ArgutiteGeO2Tet. 4/mmm(4/m2/m2/m) : P42/mnm
CassiteriteSnO2Tet. 4/mmm(4/m2/m2/m) : P42/mnm
ParatelluriteTeO2Tet. 422
PlattneritePbO2Tet. 4/mmm(4/m2/m2/m) : P42/mnm
RutileTiO2Tet. 4/mmm(4/m2/m2/m) : P42/mnm
TripuhyiteFe3+Sb5+O4Tet. 4/mmm(4/m2/m2/m) : P42/mnm
'UM2000-35-O:FeNbScTaTi'(Sc,Fe2+,Fe3+,Mn)(Ti,Sn,Zr)1.5(Nb,Ta,W)1.33O8

Common AssociatesHide

Associations Based on Photo Data:
146 photos of Pyrolusite associated with GoethiteFe3+O(OH)
124 photos of Pyrolusite associated with CalciteCaCO3
86 photos of Pyrolusite associated with QuartzSiO2
56 photos of Pyrolusite associated with Nsutite(Mn4+,Mn2+)(O,OH)2
52 photos of Pyrolusite associated with ManganiteMn3+O(OH)
45 photos of Pyrolusite associated with BrauniteMn2+Mn3+6(SiO4)O8
43 photos of Pyrolusite associated with BaryteBaSO4
39 photos of Pyrolusite associated with Romanèchite(Ba,H2O)2(Mn4+,Mn3+)5O10
34 photos of Pyrolusite associated with CryptomelaneK(Mn4+7Mn3+)O16
30 photos of Pyrolusite associated with 'Wad'

Related Minerals - Strunz-mindat GroupingHide

4.DB.TianhongqiiteCrTiO3(OH)Mon. 2/m
4.DB.NioboheftetjerniteScNbO4Mon. 2/m : P21/b
4.DB.HuangshaniteFe3+TaO4Mon. 2/m : P2/b
4.DB.Nioboixiolite-(Mn2+)(Nb0.67Mn2+0.33)O2Orth. mmm(2/m2/m2/m) : Pbcn
4.DB.Shakhdaraite-(Y)ScYNb2O8Mon. 2/m : P2/b
4.DB.05VarlamoffiteSn1-xFexO2-x(OH)
4.DB.05ArgutiteGeO2Tet. 4/mmm(4/m2/m2/m) : P42/mnm
4.DB.05CassiteriteSnO2Tet. 4/mmm(4/m2/m2/m) : P42/mnm
4.DB.05RutileTiO2Tet. 4/mmm(4/m2/m2/m) : P42/mnm
4.DB.05PlattneritePbO2Tet. 4/mmm(4/m2/m2/m) : P42/mnm
4.DB.05TripuhyiteFe3+Sb5+O4Tet. 4/mmm(4/m2/m2/m) : P42/mnm
4.DB.05TugarinoviteMoO2Mon. 2/m : P21/b
4.DB.10ByströmiteMgSb2O6Tet. 4/mmm(4/m2/m2/m) : P4/nmm
4.DB.10OrdoñeziteZnSb2O6Tet. 4/mmm(4/m2/m2/m) : P42/mnm
4.DB.10TredouxiteNiSb2O6Tet. 4/mmm(4/m2/m2/m) : P42/mnm
4.DB.10Tapiolite-(Mn)Mn2+Ta2O6Tet. 4/mmm(4/m2/m2/m) : P42/mnm
4.DB.10Tapiolite-(Fe)Fe2+Ta2O6Tet. 4/mmm(4/m2/m2/m) : P42/mnm
4.DB.15aParamontroseiteV4+O2Orth. mmm(2/m2/m2/m)
4.DB.15aRamsdelliteMn4+O2Orth. mmm(2/m2/m2/m)
4.DB.15bAkhtenskiteε-Mn4+O2Hex. 6/mmm(6/m2/m2/m) : P63/mmc
4.DB.15cNsutite(Mn4+,Mn2+)(O,OH)2Hex.
4.DB.20Scrutinyiteα-PbO2Orth. mmm(2/m2/m2/m) : Pbcn
4.DB.20Nioboixiolite-([])(Nb0.80.2)4+O2Orth. mmm(2/m2/m2/m) : Pbcn
4.DB.25IshikawaiteU4+Fe2+Nb2O8Mon.
4.DB.25Yttrocolumbite-(Y)Y(U4+,Fe2+)Nb2O8
4.DB.25Calciosamarskite(Ca,U4+)Fe3+(Nb,Ta,Ti)2O8Orth. mmm(2/m2/m2/m)
4.DB.25Samarskite-(Yb)YbFe3+(Nb,Ta)2O8Mon. 2/m : P2/b
4.DB.25Ixiolite-(Sc)(Ta0.5Sc0.5)O2Orth. mmm(2/m2/m2/m) : Pbcn
4.DB.25Ixiolite-(Fe2+)(Ta0.67Fe2+0.33)O2Orth. mmm(2/m2/m2/m) : Pbcn
4.DB.25Ixiolite-(Mn2+)(Ta0.67Mn2+0.33)O2Orth. mmm(2/m2/m2/m) : Pbcn
4.DB.25Nioboixiolite-(Fe2+)(Nb0.67Fe2+0.33)O2Orth. mmm(2/m2/m2/m) : Pbcn
4.DB.25SrilankiteTiO2Orth. mmm(2/m2/m2/m) : Pbcn
4.DB.25Samarskite-(Y)YFe3+Nb2O8Mon. 2/m : P2/b
4.DB.25Nioboixiolite-(Fe3+)(Nb0.5Fe3+0.5)O2Orth. mmm(2/m2/m2/m) : Pbcn
4.DB.30 vaWolframite Group
4.DB.30Rossovskyite(Fe3+,Ta)(Nb,Ti)O4Mon. 2/m : P2/b
4.DB.30HuanzalaiteMgWO4Mon. 2/m : P2/b
4.DB.30HeftetjerniteScTaO4Mon. 2/m : P2/b
4.DB.30HübneriteMnWO4Mon. 2/m : P2/b
4.DB.30Sanmartinite(Zn,Fe)WO4Mon. 2/m : P21/b
4.DB.30FerberiteFeWO4Mon. 2/m : P2/b
4.DB.30'Krasnoselskite'CoWO4Mon.
4.DB.35Qitianlingite(Fe,Mn)2(Nb,Ta)2WO10Orth. mmm(2/m2/m2/m)
4.DB.35Tantalaeschynite-(Ce)Ce(TiTa)O6Orth. mmm(2/m2/m2/m) : Pnma
4.DB.35Tantalite-(Mg)(Mg,Fe2+)(Ta,Nb)2O6Orth. mmm(2/m2/m2/m) : Pbcn
4.DB.35Columbite-(Mn)Mn2+Nb2O6Orth. mmm(2/m2/m2/m) : Pbcn
4.DB.35Tantalite-(Mn)Mn2+Ta2O6Orth. mmm(2/m2/m2/m) : Pbcn
4.DB.35Columbite-(Fe)Fe2+Nb2O6Orth. mmm(2/m2/m2/m) : Pbcn
4.DB.35Columbite-(Mg)(Mg,Fe,Mn)(Nb,Ta)2O6Orth.
4.DB.35Tantalite-(Fe)Fe2+Ta2O6Orth. mmm(2/m2/m2/m) : Pbcn
4.DB.40FerrotitanowodginiteFe2+TiTa2O8Mon. 2/m : B2/b
4.DB.40'Wolframowodginite'Mn(Mn,Sn,Fe,Ta)(W,Ta,Nb)2O8
4.DB.40LithiotantiteLiTa3O8Mon. 2/m : P21/b
4.DB.40LithiowodginiteLiTa3O8Mon. 2/m : B2/b
4.DB.40TitanowodginiteMn2+TiTa2O8Mon. 2/m : B2/b
4.DB.40Tantalowodginite(Mn2+0.50.5)TaTa2O8Mon. 2/m : B2/b
4.DB.40WodginiteMn2+Sn4+Ta2O8Mon. 2/m : B2/b
4.DB.40FerrowodginiteFe2+Sn4+Ta2O8Mon. 2/m : B2/b
4.DB.45TivaniteV3+TiO3(OH)Mon. 2/m : P21/b
4.DB.50Carmichaelite(Ti,Cr,Fe)[O2-x(OH)x]Mon. 2/m : P21/b
4.DB.55AlumotantiteAlTaO4Orth. mmm(2/m2/m2/m) : Pbcn
4.DB.60Biehlite((Sb,As)O)2[MoO4]Mon. 2/m : B2/b

Fluorescence of PyrolusiteHide

Other InformationHide

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 PyrolusiteHide

References for PyrolusiteHide

Reference List:

Localities for PyrolusiteHide

Showing 3,870 localities.

This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.
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