Pyrochroite
A valid IMA mineral species - grandfathered
This page is currently not sponsored. Click here to sponsor this page.
About Pyrochroite
Formula:
Mn(OH)2
Colour:
Colourless, greenish, bluish (fresh), brown to black (exposed); flesh-red or amethystine in transmitted light
Lustre:
Pearly
Hardness:
2½ - 3
Specific Gravity:
3.23 - 3.27
Crystal System:
Trigonal
Member of:
Name:
Named in 1864 by Lars Johan Igelstrom from the Greek πύρ, "fire", and χρώσις, "colouring", in allusion to the change of color upon ignition.
Occurs as either a hydration product of manganosite (MnO) or as a primary mineral in some volcanogenic massive sulfide (VMS) deposits.
Unique Identifiers
Mindat ID:
3317
Long-form identifier:
mindat:1:1:3317:2
GUID
(UUID V4):
(UUID V4):
836ae4d3-c4d9-4c00-af5d-95b9901e0cb9
IMA Classification of Pyrochroite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
Mn2+(OH)2
Type description reference:
Classification of Pyrochroite
4.FE.05
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
F : Hydroxides (without V or U)
E : Hydroxides with OH, without H2O; sheets of edge-sharing octahedra
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
F : Hydroxides (without V or U)
E : Hydroxides with OH, without H2O; sheets of edge-sharing octahedra
6.2.1.3
6 : HYDROXIDES AND OXIDES CONTAINING HYDROXYL
2 : X(OH)2
6 : HYDROXIDES AND OXIDES CONTAINING HYDROXYL
2 : X(OH)2
7.18.10
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 |
---|---|---|
Pyc | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Pyc | The Canadian Mineralogist (2019) | The Canadian Mineralogist (2019) The Canadian Mineralogist list of symbols for rock- and ore-forming minerals (December 30, 2019). download |
Pyc | Warr (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 |
Physical Properties of Pyrochroite
Pearly
Transparency:
Translucent, Opaque
Comment:
Pearly on cleavages
Colour:
Colourless, greenish, bluish (fresh), brown to black (exposed); flesh-red or amethystine in transmitted light
Hardness:
2½ - 3 on Mohs scale
Tenacity:
Elastic
Cleavage:
Perfect
On {0001}
On {0001}
Density:
3.23 - 3.27 g/cm3 (Measured) 3.25 g/cm3 (Calculated)
Optical Data of Pyrochroite
Type:
Uniaxial (-)
RI values:
nω = 1.680 - 1.681 nε = 1.720 - 1.723
Max Birefringence:
δ = 0.040
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
and does not take into account mineral colouration.
Surface Relief:
High
Pleochroism:
Visible
Comments:
Dichroic: O = brown; E = lighter brown.
Comments:
Strongly reflecting in polished section (black altered material).
Chemistry of Pyrochroite
Mindat Formula:
Mn(OH)2
Elements listed:
Crystallography of Pyrochroite
Crystal System:
Trigonal
Class (H-M):
3m (3 2/m) - Hexagonal Scalenohedral
Space Group:
P3m1
Setting:
P3m1
Cell Parameters:
a = 3.33(1) Å, c = 4.70(2) Å
Ratio:
a:c = 1 : 1.411
Unit Cell V:
45.14 ų (Calculated from Unit Cell)
Z:
1
Morphology:
Crystals tabular {0001}; also less commonly rhombohedral with large {1012} or {1011}. Rarely prismatic [0001] with {1120} and {0001} developed. Foliated masses.
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) |
---|---|---|---|---|---|---|---|
0008112 | Pyrochroite | Parise J B, Theroux B, Li R, Loveday J S, Marshall W G, Klotz S (1998) Pressure dependence of hydrogen bonding in metal deuteroxides: a neutron powder diffraction study of Mn(OD)2 and beta-Co(OD)2. Physics and Chemistry of Minerals 25 130-137 | 1998 | 0 | 293 | ||
0008113 | Pyrochroite | Parise J B, Theroux B, Li R, Loveday J S, Marshall W G, Klotz S (1998) Pressure dependence of hydrogen bonding in metal deuteroxides: a neutron powder diffraction study of Mn(OD)2 and beta-Co(OD)2. Physics and Chemistry of Minerals 25 130-137 | 1998 | 0.7 | 293 | ||
0008114 | Pyrochroite | Parise J B, Theroux B, Li R, Loveday J S, Marshall W G, Klotz S (1998) Pressure dependence of hydrogen bonding in metal deuteroxides: a neutron powder diffraction study of Mn(OD)2 and beta-Co(OD)2. Physics and Chemistry of Minerals 25 130-137 | 1998 | 2.4 | 293 | ||
0008115 | Pyrochroite | Parise J B, Theroux B, Li R, Loveday J S, Marshall W G, Klotz S (1998) Pressure dependence of hydrogen bonding in metal deuteroxides: a neutron powder diffraction study of Mn(OD)2 and beta-Co(OD)2. Physics and Chemistry of Minerals 25 130-137 | 1998 | 4.6 | 293 | ||
0008116 | Pyrochroite | Parise J B, Theroux B, Li R, Loveday J S, Marshall W G, Klotz S (1998) Pressure dependence of hydrogen bonding in metal deuteroxides: a neutron powder diffraction study of Mn(OD)2 and beta-Co(OD)2. Physics and Chemistry of Minerals 25 130-137 | 1998 | 7.8 | 293 | ||
0011790 | Pyrochroite | Wyckoff R W G (1963) Second edition. Interscience Publishers, New York, New York Crystal Structures 1 239-444 | 1963 | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
4.6 Å | (10) |
2.48 Å | (3) |
2.76 Å | (2) |
1.542 Å | (2) |
3.09 Å | (1) |
2.41 Å | (1) |
2.04 Å | (1) |
Geological Environment
Paragenetic Mode(s):
Paragenetic Mode | Earliest Age (Ga) |
---|---|
High-𝑇 alteration and/or metamorphism | |
32 : Ba/Mn/Pb/Zn deposits, including metamorphic deposits | |
33 : Minerals deposited by hydrothermal metal-rich fluids (see also [#12]) | |
Stage 7: Great Oxidation Event | <2.4 |
47a : [Near-surface hydration of prior minerals] |
Type Occurrence of Pyrochroite
Reference:
Igelström L J (1864) Pyrochroït, ein neues Mineral. Annalen der Physik und Chemie 122, 181-182
Synonyms of Pyrochroite
Manganese Oxides (in part)
Other Language Names for Pyrochroite
Relationship of Pyrochroite to other Species
Member of:
Other Members of this group:
Amakinite | Fe2+(OH)2 | Trig. |
Brucite | Mg(OH)2 | Trig. 3m (3 2/m) : P3m1 |
Portlandite | Ca(OH)2 | Trig. 3m (3 2/m) : P3m1 |
Theophrastite | Ni(OH)2 | Trig. 3m (3 2/m) : P3m1 |
Common Associates
Associated Minerals Based on Photo Data:
43 photos of Pyrochroite associated with Lead | Pb |
40 photos of Pyrochroite associated with Zincite | ZnO |
34 photos of Pyrochroite associated with Calcite | CaCO3 |
23 photos of Pyrochroite associated with Hydrocerussite | Pb3(CO3)2(OH)2 |
20 photos of Pyrochroite associated with Sussexite | Mn2+BO2(OH) |
19 photos of Pyrochroite associated with Mooreite | Mg9◻2Mn2Zn4(SO4)2(OH)26 · 8H2O |
19 photos of Pyrochroite associated with Willemite | Zn2SiO4 |
17 photos of Pyrochroite associated with Torreyite | (Mg,Mn2+)7◻2Mn2+2Zn4(SO4)2(OH)22 · 8H2O |
16 photos of Pyrochroite associated with Allactite | Mn2+7(AsO4)2(OH)8 |
14 photos of Pyrochroite associated with Leucophoenicite | Mn2+7(SiO4)3(OH)2 |
Related Minerals - Strunz-mindat Grouping
4.FE.05 | Amakinite | Fe2+(OH)2 |
4.FE.05 | Brucite | Mg(OH)2 |
4.FE.05 | Portlandite | Ca(OH)2 |
4.FE.05 | Theophrastite | Ni(OH)2 |
4.FE.10 | Bayerite | Al(OH)3 |
4.FE.10 | Doyleite | Al(OH)3 |
4.FE.10 | Gibbsite | Al(OH)3 |
4.FE.10 | Nordstrandite | Al(OH)3 |
4.FE.15 | Böhmite | AlO(OH) |
4.FE.15 | Lepidocrocite | γ-Fe3+O(OH) |
4.FE.20 | Grimaldiite | CrO(OH) |
4.FE.20 | Heterogenite | Co3+O(OH) |
4.FE.25 | Feitknechtite | Mn3+O(OH) |
4.FE.25 | Lithiophorite | (Al,Li)MnO2(OH)2 |
4.FE.30 | Quenselite | PbMnO2(OH) |
4.FE.35 | Ferrihydrite | Fe3+10O14(OH)2 |
4.FE.40 | Feroxyhyte | Fe3+O(OH) |
4.FE.40 | Vernadite | (Mn4+,Fe3+,Ca,Na)(O,OH)2 · nH2O |
4.FE.45 | Quetzalcoatlite | Zn6Cu3(TeO6)2(OH)6 · AgxPbyClx+2y |
4.FE.50 | Fuettererite | Pb3Cu2+6Te6+O6(OH)7Cl5 |
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 Pyrochroite
mindat.org URL:
https://www.mindat.org/min-3317.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 Pyrochroite
Localities for Pyrochroite
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).
Struck out - Mineral was erroneously reported from this locality.
Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).
All localities listed without proper references should be considered as questionable.
All localities listed without proper references should be considered as questionable.
Atlantic Ocean | |
| Gablina et al. (2006) |
Burkina Faso | |
| Kříbek et al. (2016) |
Canada | |
| 179-181. +2 other references |
China | |
| Zhao et al. (2024) |
| Zhongtang Yang et al. (2008) +1 other reference |
| Yeh et al. (1999) |
| Xingfen Wang (1989) +1 other reference |
| Hongjun Qu (1992) |
| Hongjun Qu (1992) |
Hongjun Qu (1992) | |
| Zhangxiang Peng (1990) |
Egypt | |
| El-Habaak et al. (2016) |
| Manganese Reserves and Resources of the ... |
Germany | |
| Schnorrer et al. (2001) |
Ghana | |
| Mineralium Deposita Volume 34 Issue 3 (1999) |
India | |
| Rao et al. (1979) |
Italy | |
| Parola et al. (2023) |
| Published on LIBVRNA N°1 may 2021. Analysed by Spectralab srl (SEM/EDS and Raman) |
Japan | |
| Mayumi Yoshinaga (1963) |
| Kato (2010) |
| Matsubara Satoshi et al. (1980) |
| Okamoto collection (curated at the Geological Survey museum, Japan) +2 other references |
| Mayumi Yoshinaga (1963) |
| |
| Fuzimoto (2006) |
| Akira Kato (2011) |
Akira Kato (2011) | |
| Yoshinaga et al. (1963) |
| Akira Kato (undated manuscript) +2 other references |
| Mayumi Yoshinaga (1963) |
| Fumitoshi HIROWATARI (1961) |
Mayumi Yoshinaga (1963) | |
Namibia | |
| Dunn (1991) |
Poland | |
| Ł. Kruszewski PXRD & pXRF data (paper in preparation) |
Romania | |
| minerals-of-the-carpathians.eu (2008) |
| Hîrtopanu (1997) +1 other reference |
Russia | |
| Kassandrov et al. (2009) |
Kassandrov et al. (2009) | |
| Talovina et al. (2003) |
Saudi Arabia | |
| Gahlan et al. (2021) |
South Africa | |
| Mitchell et al. (2004) |
| Von Bezing et al. (1991) |
Pohl et al. (1991) | |
Pohl et al. (1991) | |
Spain | |
| Mendoza et al. (2006) |
Sweden | |
| Gatedal (n.d.) |
| |
| Gatedal (n.d.) |
Palache et al. (1951) +1 other reference | |
Flink (1922) | |
Österberg (2003) | |
| Gatedal (n.d.) |
| Moore (1978) |
Holtstam et al. (1998) | |
Flink (1886) +2 other references | |
| Nysten (1984) |
| [Am Min 50 (1965) +1 other reference |
Switzerland | |
| Die Mineralien der Schweiz |
UK | |
| Bernie Millington Collection |
| R. E. Bevins (1988) |
USA | |
| Prenn et al. (1991) |
| Mineralogical Record (1991) |
| www.mineralsocal.org +3 other references |
| ... |
| Castor et al. (2004) |
| Palache (1935) +1 other reference |
King | |
Palache (1935) | |
Palache (1935) | |
| Palache (1935) +1 other reference |
Peter Chin |
Quick NavTopAbout PyrochroiteUnique 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
Wessels Mine, Joe Morolong Local Municipality, John Taolo Gaetsewe District Municipality, Northern Cape, South Africa