Donpeacorite
A valid IMA mineral species
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About Donpeacorite
Donald R. Peacor
Formula:
Mn2+MgSi2O6
Mn may be partially substituted by Mg.
Colour:
Pale buff, yellow-orange; faint pink in thin section.
Lustre:
Vitreous
Hardness:
5 - 6
Specific Gravity:
3.36
Crystal System:
Orthorhombic
Member of:
Name:
Named in 1984 by Erich U. Petersen, Lawrence M. Anovitz, and Eric J. Essene in honor of Donald Ralph Peacor [b. 1937 Somerville, Massachusetts, USA], mineralogist at the University of Michigan, in recognition of his work on pyroxenes and manganese minerals. He authored/coauthored descriptions of approximately 90 new minerals and worked on the structure of many others.
Dimorph of:
This page provides mineralogical data about Donpeacorite.
Unique Identifiers
Mindat ID:
1310
Long-form identifier:
mindat:1:1:1310:5
IMA Classification of Donpeacorite
Approved
First published:
1984
Classification of Donpeacorite
9.DA.05
9 : SILICATES (Germanates)
D : Inosilicates
A : Inosilicates with 2-periodic single chains, Si2O6; pyroxene family
9 : SILICATES (Germanates)
D : Inosilicates
A : Inosilicates with 2-periodic single chains, Si2O6; pyroxene family
65.1.2.3
65 : INOSILICATES Single-Width,Unbranched Chains,(W=1)
1 : Single-Width Unbranched Chains, W=1 with chains P=2
65 : INOSILICATES Single-Width,Unbranched Chains,(W=1)
1 : Single-Width Unbranched Chains, W=1 with chains P=2
14.18.7
14 : Silicates not Containing Aluminum
18 : Silicates of Mn and Na, K, Mg, Ca or Fe
14 : Silicates not Containing Aluminum
18 : Silicates of Mn and Na, K, Mg, Ca or Fe
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 |
|---|---|---|
| Don | 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 Donpeacorite
Vitreous
Transparency:
Translucent
Colour:
Pale buff, yellow-orange; faint pink in thin section.
Hardness:
5 - 6 on Mohs scale
Cleavage:
Perfect
{110}
{110}
Density:
3.36(1) g/cm3 (Measured) 3.403(2) g/cm3 (Calculated)
Optical Data of Donpeacorite
Type:
Biaxial (-)
RI values:
nα = 1.677 nβ = 1.684 nγ = 1.692
2V:
Measured: 88° , Calculated: 88°
Max. Birefringence:
δ = 0.015
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:
Very High (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
Chemistry of Donpeacorite
Mindat Formula:
Mn2+MgSi2O6
Mn may be partially substituted by Mg.
Mn may be partially substituted by Mg.
Element Weights:
Elements listed:
Common Impurities:
Al,Fe,Ca,Na
Chemical Analysis
Oxide wt%:
| 1 | |
|---|---|
| SiO2 | 55.02 % |
| TiO2 | 0.05 % |
| Al2O3 | 0.19 % |
| Mn2O3* | 1.06 % |
| Fe2O3* | 0.27 % |
| MnO* | 17.77 % |
| MgO | 26.40 % |
| CaO | 0.58 % |
| SrO | 0.01 % |
| Total: | 101.35 % |
Empirical formulas:
| Sample ID | Empirical Formula |
|---|---|
| 1 | (Mn2+0.54Mg0.44Ca0.02)(Mg0.97Mn3+0.03)[Si1.98Al0.01Fe3+0.01O6] |
Sample references:
| ID | Locality | Reference | Notes |
|---|---|---|---|
| 1 | Empire State No. 4 Mine, Balmat, Fowler, St. Lawrence County, New York, USA | Donpeacorite intergrown with clino-suenoite ("manganocummingtonite"), minor uvite, and rare scattered turneaureite. Analysis by EPMA. *Fe3+/∑Fe and Mn3+/∑Mn calculated by charge balance, with all Fe assigned to Fe3+ before any Mn is assigned to Mn3+. Site assignments are based only on the expected filling sequence and are not verified by structural evidence. |
Crystallography of Donpeacorite
Crystal System:
Orthorhombic
Class (H-M):
mmm(2/m2/m2/m) - Dipyramidal
Space Group:
Pbca
Setting:
Pbca
Cell Parameters:
a = 18.38 Å, b = 8.87 Å, c = 5.22 Å
Ratio:
a:b:c = 2.072 : 1 : 0.589
Unit Cell V:
851.02 ų (Calculated from Unit Cell)
Z:
8
Crystal Structure
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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) |
|---|---|---|---|---|---|---|---|
| 0003672 | Donpeacorite | Stimpfl M (2005) The Mn, Mg-intracrystalline exchange reaction in donpeacorite (Mn0.54Ca0.03Mg1.43Si2O6) and its relation to the fractionation behavior of Mn in Fe, Mg-orthopyroxene American Mineralogist 90 155-161 |  | 2005 | 0 | 293 | |
| 0003671 | Donpeacorite | Stimpfl M (2005) The Mn, Mg-intracrystalline exchange reaction in donpeacorite (Mn0.54Ca0.03Mg1.43Si2O6) and its relation to the fractionation behavior of Mn in Fe, Mg-orthopyroxene American Mineralogist 90 155-161 | | 2005 | 0 | 293 | |
| 0003670 | Donpeacorite | Stimpfl M (2005) The Mn, Mg-intracrystalline exchange reaction in donpeacorite (Mn0.54Ca0.03Mg1.43Si2O6) and its relation to the fractionation behavior of Mn in Fe, Mg-orthopyroxene American Mineralogist 90 155-161 | | 2005 | 0 | 293 | |
| 0003669 | Donpeacorite | Stimpfl M (2005) The Mn, Mg-intracrystalline exchange reaction in donpeacorite (Mn0.54Ca0.03Mg1.43Si2O6) and its relation to the fractionation behavior of Mn in Fe, Mg-orthopyroxene American Mineralogist 90 155-161 | | 2005 | 0 | 293 | |
| 0003668 | Donpeacorite | Stimpfl M (2005) The Mn, Mg-intracrystalline exchange reaction in donpeacorite (Mn0.54Ca0.03Mg1.43Si2O6) and its relation to the fractionation behavior of Mn in Fe, Mg-orthopyroxene American Mineralogist 90 155-161 | | 2005 | 0 | 293 | |
| 0003667 | Donpeacorite | Stimpfl M (2005) The Mn, Mg-intracrystalline exchange reaction in donpeacorite (Mn0.54Ca0.03Mg1.43Si2O6) and its relation to the fractionation behavior of Mn in Fe, Mg-orthopyroxene American Mineralogist 90 155-161 | | 2005 | 0 | 293 | |
| 0000937 | Donpeacorite | Petersen E U, Anovitz L M, Essene E J (1984) Donpeacorite, (Mn,Mg)MgSi2O6, a new orthopyroxene and its proposed phase relations in the system MnSiO3-MgSiO3-FeSiO3 American Mineralogist 69 472-480 | | 1984 | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 3.18 Å | (100) |
| 2.896 Å | (60) |
| 1.495 Å | (11) |
| 1.479 Å | (11) |
| 4.03 Å | (10) |
| 3.09 Å | (10) |
| 2.96 Å | (10) |
Comments:
Empire State Mine, New York, USA. Data from type description.
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 2: Planetesimal differentiation and alteration | 4.566-4.550 |
| 6 : Secondary asteroid phases | 4.566-4.560 |
| High-? alteration and/or metamorphism | |
| 32 : Ba/Mn/Pb/Zn deposits, including metamorphic deposits | |
| Stage 5: Initiation of plate tectonics | <3.5-2.5 |
| 40 : Regional metamorphism (greenschist, amphibolite, granulite facies) |
Type Occurrence of Donpeacorite
General Appearance of Type Material:
Interlocking grains up to 3 mm.
Place of Conservation of Type Material:
Harvard University, Cambridge, Massachusetts, 124237; National Museum of Natural History, Washington, D.C., USA, 159862.
Geological Setting of Type Material:
manganese-rich siliceous marbles metamorphosed to the upper amphibolite facies
Associated Minerals at Type Locality:
Other Language Names for Donpeacorite
Relationship of Donpeacorite to other Species
Member of:
Other Members of Orthopyroxene Subgroup:
| Enstatite | Mg2Si2O6 | Orth. mmm(2/m2/m2/m) : Pbca |
| Ferrosilite | Fe2+2Si2O6 | Orth. mmm(2/m2/m2/m) : Pbca |
| Protoenstatite | Mg2Si2O6 | Orth. mmm(2/m2/m2/m) : Pbcn |
Common Associates
Associations Based on Photo Data:
| 14 photos of Donpeacorite associated with Turneaureite | Ca5(AsO4)3Cl |
| 4 photos of Donpeacorite associated with Braunite | Mn2+Mn3+6(SiO4)O8 |
| 2 photos of Donpeacorite associated with Clino-suenoite | ◻Mn2+2(Mg5)(Si8O22)(OH)2 |
Related Minerals - Strunz-mindat Grouping
| 9.DA. | Colomeraite | NaTi3+Si2O6 |
| 9.DA. | Protoenstatite | Mg2Si2O6 |
| 9.DA. | Ryabchikovite | CuMgSi2O6 |
| 9.DA.05 | Enstatite | Mg2Si2O6 |
| 9.DA.05 | Ferrosilite | Fe2+2Si2O6 |
| 9.DA.10 | Clinoenstatite | MgSiO3 |
| 9.DA.10 | Clinoferrosilite | Fe2+2Si2O6 |
| 9.DA.10 | Kanoite | Mn2+MgSi2O6 |
| 9.DA.10 | Pigeonite | (CaxMgyFez)(Mgy1Fez1)Si2O6 |
| 9.DA.15 | Grossmanite | CaTi3+ AlSiO6 |
| 9.DA.15 | Diopside | CaMgSi2O6 |
| 9.DA.15 va | 'Jeffersonite' | Ca(Mn,Zn,Fe)Si2O6 |
| 9.DA.15 | Hedenbergite | CaFe2+Si2O6 |
| 9.DA.15 | Johannsenite | CaMn2+Si2O6 |
| 9.DA.15 | Petedunnite | CaZnSi2O6 |
| 9.DA.15 | Esseneite | CaFe3+[AlSiO6] |
| 9.DA.15 | Kushiroite | CaAlAlSiO6 |
| 9.DA.15 | Augite | (CaxMgyFez)(Mgy1Fez1)Si2O6 |
| 9.DA.15 | Davisite | CaScAlSiO6 |
| 9.DA.20 | Aegirine-augite | (NaaCabFe2+cMgd)(Fe3+eAlfFe2+gMgh)Si2O6 |
| 9.DA.20 | Omphacite | (NaaCabFe2+cMgd)(AleFe3+fFe2+gMgh)Si2O6 |
| 9.DA.25 | Jadeite | Na(Al,Fe3+)Si2O6 |
| 9.DA.25 | Namansilite | NaMn3+Si2O6 |
| 9.DA.25 | Natalyite | NaV3+Si2O6 |
| 9.DA.25 | Aegirine | NaFe3+Si2O6 |
| 9.DA.25 | Jervisite | NaSc3+Si2O6 |
| 9.DA.25 | Tissintite | (Ca,◻)AlSi2O6 |
| 9.DA.25 | Kosmochlor | NaCrSi2O6 |
| 9.DA.30 | Spodumene | LiAlSi2O6 |
| 9.DA.35 | Hiroseite | FeSiO3 |
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 Donpeacorite
mindat.org URL:
https://www.mindat.org/min-1310.html
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Please feel free to link to this page.
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References for Donpeacorite
Reference List:
Peterson, Erich U., Anovitz, Lawrence M., Essene, Eric J. (1984) Donpeacorite, (Mn,Mg)MgSi2O6, a new orthopyroxene and its proposed phase relations in the system MnSiO3-MgSiO3-FeSiO3. American Mineralogist, 69 (5-6). 472-480
Localities for Donpeacorite
Showing 5 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.
Japan | |
| kensou.shinshu-u.ac.jp (n.d.) |
Jordan | |
| Yaseen (2014) |
Mongolia | |
| Davaasuren et al. (2016) |
United Arab Emirates | |
| Gnos et al. (1996) +1 other reference |
USA (TL) | |
| Fleischer's Glossary of Mineral Species ... +2 other references |
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Empire State No. 4 Mine, Balmat, Fowler, St. Lawrence County, New York, USA