Dorrite
A valid IMA mineral species
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About Dorrite
John A. Dorr
Formula:
Ca4(Mg3Fe3+9)O4(Si3Al8Fe3+O36)
Idealized formula for Kopeisk material: Ca4Mg4Fe3+8[Al8Si4O20]
Colour:
red-brown, brown-black, dark brown
Lustre:
Sub-Metallic
Hardness:
5½
Specific Gravity:
3.059 (Calculated)
Crystal System:
Triclinic
Member of:
Name:
Named by Michael A. Cosca, Roland R. Rouse, and Eric J. Essene in 1987 in honor of John A. "Jack" Dorr, Jr. (1922/3 - 8 April 1986), Professor of Geology, University of Michigan, Ann Arbor, Michigan, USA, in recognition of his geologic research in Wyoming.
Stable in strongly oxidizing, high-temperature low-pressure environments.
Site occupancy for dorrite from Kopeisk (Shchipalkina et al., 2016), is: M1: (Fe3+,Mg); M2: (Fe3+,Mg); M3: 2(Fe3+,Mg); M4: 2(Fe3+,Mg); M5: 2Mg; M6: 2(Mg,Fe3+); M7: 2(Fe3+,Al); M8: 2Ca; M9: 2Ca; T1: 2(Si,Al); T2: 2(Si,Al); T3: 2Al; T4: 2Si; T5: 2(Al,Fe3+); T6: 2(Al,Fe3+).
Site occupancy for dorrite from Kopeisk (Shchipalkina et al., 2016), is: M1: (Fe3+,Mg); M2: (Fe3+,Mg); M3: 2(Fe3+,Mg); M4: 2(Fe3+,Mg); M5: 2Mg; M6: 2(Mg,Fe3+); M7: 2(Fe3+,Al); M8: 2Ca; M9: 2Ca; T1: 2(Si,Al); T2: 2(Si,Al); T3: 2Al; T4: 2Si; T5: 2(Al,Fe3+); T6: 2(Al,Fe3+).
Unique Identifiers
Mindat ID:
1313
Long-form identifier:
mindat:1:1:1313:6
GUID
(UUID V4):
(UUID V4):
aabd2b94-dc6b-44a4-b877-48494b3c17fc
IMA Classification of Dorrite
Approved
IMA Formula:
Ca4[Mg3Fe3+9]O4[Si3Al8Fe3+O36]
Approval year:
1987
First published:
1988
Classification of Dorrite
9.DH.40
9 : SILICATES (Germanates)
D : Inosilicates
H : Inosilicates with 4-periodic single chains, Si4O12
9 : SILICATES (Germanates)
D : Inosilicates
H : Inosilicates with 4-periodic single chains, Si4O12
69.2.1a.2
69 : INOSILICATES Chains with Side Branches or Loops
2 : Chains with Side Branches or Loops with P>2
69 : INOSILICATES Chains with Side Branches or Loops
2 : Chains with Side Branches or Loops with P>2
16.23.2
16 : Silicates Containing Aluminum and other Metals
23 : Aluminosilicates of Fe, Ca, and Mg
16 : Silicates Containing Aluminum and other Metals
23 : Aluminosilicates of Fe, Ca, and Mg
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 |
|---|---|---|
| Dor | 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 Dorrite
Sub-Metallic
Transparency:
Opaque
Colour:
red-brown, brown-black, dark brown
Streak:
brownish grey
Hardness:
5½ on Mohs scale
Tenacity:
Brittle
Cleavage:
Distinct/Good
Good on {010} and {001}.
Good on {010} and {001}.
Fracture:
Irregular/Uneven
Density:
3.059 g/cm3 (Calculated)
Optical Data of Dorrite
Type:
Biaxial (-)
RI values:
nα = 1.820(1) nβ = 1.840(1) nγ = 1.860(1)
2V:
Measured: 90° , Calculated: 88°
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:
Very High
Dispersion:
small
Pleochroism:
Strong
Comments:
X = red-orange brown; Y = yellowish brown; Z = greenish brown.
Chemistry of Dorrite
Mindat Formula:
Ca4(Mg3Fe3+9)O4(Si3Al8Fe3+O36)
Idealized formula for Kopeisk material: Ca4Mg4Fe3+8[Al8Si4O20]
Idealized formula for Kopeisk material: Ca4Mg4Fe3+8[Al8Si4O20]
Common Impurities:
Ti,Cr,Mn,Na,K
Crystallography of Dorrite
Crystal System:
Triclinic
Cell Parameters:
a = 10.5 Å, b = 10.89 Å, c = 9.91 Å
α = 106.26°, β = 95.16°, γ = 124.75°
α = 106.26°, β = 95.16°, γ = 124.75°
Ratio:
a:b:c = 0.964 : 1 : 0.91
Unit Cell V:
847.91 ų (Calculated from Unit Cell)
Morphology:
As anhedral to prismatic grains, to 0.1 mm; some grains exhibit hopper and skeletal habits
Twinning:
Twinned by two-fold rotation about the pseudomonoclinic [010] axis.
Comment:
Point Group: 1 or 1 . ; Space Group: P1 or P1 .
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 2.971 Å | (100) |
| 2.558 Å | (80) |
| 2.515 Å | (80) |
| 2.125 Å | (60) |
| 1.511 Å | (30) |
| 1.482 Å | (30) |
| 8.1 Å | (20) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 47h : [Near-surface oxidized, dehydrated minerals] | |
| Stage 10a: Neoproterozoic oxygenation/terrestrial biosphere | <0.6 |
| 50 : Coal and/or oil shale minerals | <0.36 |
| 51 : Pyrometamorphic minerals (see also #54 and #56) | <0.36 |
| Stage 10b: Anthropogenic minerals | <10 Ka |
| 54 : Coal and other mine fire minerals (see also #51 and #56) | |
| 56 : Slag and smelter minerals (see also #51 and #55) |
Type Occurrence of Dorrite
Place of Conservation of Type Material:
University of Michigan, Ann Arbor, Michigan; National Museum of Natural History, Washington, D.C., USA (163357).
Associated Minerals at Type Locality:
Reference:
Cosca, M.A., Rouse, R.R., Essene, E.J. (1988) Dorrite [Ca2(Mg2Fe3+4)(Al4Si2)O20], a new member of the aenigmatite group from a pyrometamorphic melt-rock. American Mineralogist: 73: 1440-1448.
Synonyms of Dorrite
Other Language Names for Dorrite
Relationship of Dorrite to other Species
Member of:
Other Members of this group:
| Høgtuvaite | Ca4[Fe2+6Fe3+6]O4[Si8Be2Al2O36] | Tric. 1 : P1 |
| Leucorhönite | Ca2(Mg,Fe3+,Al)6(Si,Al)6O20 | Tric. |
| Makarochkinite | (Ca,Na)4[Fe2+8Fe3+2Ti2]O4[Si8Be2Al2O36] | Tric. 1 : P1 |
| Rhönite | Ca4[Mg8Fe3+2Ti2]O4[Si6Al6O36] | Tric. 1 : P1 |
| Serendibite | Ca4[Mg6Al6]O4[Si6B3Al3O36] | Tric. 1 : P1 |
| Welshite | Ca4Mg9Sb3O4[Si6Be3AlFe2O36] | Tric. 1 : P1 |
Common Associates
Associated Minerals Based on Photo Data:
Related Minerals - Strunz-mindat Grouping
| 9.DH. | Gageite-2M | (Mn,Mg,Zn)42Si16O54(OH)40 |
| 9.DH. | Bavsiite | Ba2V2O2[Si4O12] |
| 9.DH. | Devilliersite | Ca4Ca2Fe3+10O4[(Fe3+10Si2)O36] |
| 9.DH. | Yuzuxiangite | Sr3Fe3+(Si2O6)2(OH) · 3H2O |
| 9.DH. | Louisfuchsite | Ca2(Mg4Ti2)(Al4Si2)O20 |
| 9.DH.05 | Leucophanite | NaCaBeSi2O6F |
| 9.DH.10 | Ohmilite | Sr3(Ti,Fe3+)(Si4O12)(O,OH) · 2-3H2O |
| 9.DH.15 | Haradaite | SrVSi2O7 |
| 9.DH.15 | Suzukiite | BaVSi2O7 |
| 9.DH.20 | Batisite | BaNaNaTi2(Si4O12)O2 |
| 9.DH.20 | Shcherbakovite | (K,Ba)KNa(Ti,Nb)2(Si4O12)O2 |
| 9.DH.20 | Noonkanbahite | BaKNaTi2(Si4O12)O2 |
| 9.DH.25 | Taikanite | Sr3BaMn2+2(Si4O12)O2 |
| 9.DH.30 | Krauskopfite | BaSi2O5 · 3H2O |
| 9.DH.35 | Balangeroite | (Mg,Fe2+,Fe3+,Mn2+)42Si16O54(OH)40 |
| 9.DH.35 | Gageite | Mn21(Si4O12)2O3(OH)20 |
| 9.DH.40 | Aenigmatite | Na4[Fe2+10Ti2]O4[Si12O36] |
| 9.DH.40 | Høgtuvaite | Ca4[Fe2+6Fe3+6]O4[Si8Be2Al2O36] |
| 9.DH.40 | Krinovite | Na2Mg4Cr3+2(Si6O18)O2 |
| 9.DH.40 | Makarochkinite | (Ca,Na)4[Fe2+8Fe3+2Ti2]O4[Si8Be2Al2O36] |
| 9.DH.40 | Rhönite | Ca4[Mg8Fe3+2Ti2]O4[Si6Al6O36] |
| 9.DH.40 | Serendibite | Ca4[Mg6Al6]O4[Si6B3Al3O36] |
| 9.DH.40 | Welshite | Ca4Mg9Sb3O4[Si6Be3AlFe2O36] |
| 9.DH.40 | Wilkinsonite | Na2Fe2+4Fe3+2(Si6O18)O2 |
| 9.DH.40 | Leucorhönite | Ca2(Mg,Fe3+,Al)6(Si,Al)6O20 |
| 9.DH.40 | Kuratite | Ca2(Fe2+5Ti)O2[Si4Al2O18] |
| 9.DH.40 | Khesinite | Ca4(Mg3Fe3+9)O4(Fe3+9Si3)O36 |
| 9.DH.40 | UM1991-29-SiO:FeMgNa | Na4(Mg5Fe3+7)O4[Si9Fe3+3O36] |
| 9.DH.45 | Sapphirine | Mg4(Mg3Al9)O4[Si3Al9O36] |
| 9.DH.50 | Khmaralite | (Mg,Al,Fe)16[(Al,Si,Be)12O36]O4 |
| 9.DH.55 | Surinamite | (Mg,Fe)3Al4BeSi3O16 |
| 9.DH.55 | UM1988-26-SiO:AlMg | Mg4Al2O[Si3Al2O15] |
| 9.DH.60 | Deerite | (Fe,Mn)6(Fe,Al)3[Si6O17]O3(OH)5 |
| 9.DH.65 | Howieite | Na(Fe,Mn)10(Fe,Al)2Si12O31(OH)13 |
| 9.DH.65 | Taneyamalite | (Na,Ca)(Mn,Mg,Fe)12Si12(O,OH)44 |
| 9.DH.70 | Johninnesite | Na2Mn2+9Mg7(OH)8[AsO4]2[Si6O17]2 |
| 9.DH.75 | Agrellite | NaCa2Si4O10F |
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 Dorrite
mindat.org URL:
https://www.mindat.org/min-1313.html
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References for Dorrite
Reference List:
Jensen, B. B. (1996) Solid solution among members of the aenigmatite group. Mineralogical Magazine, 60 (403) 982-986 doi:10.1180/minmag.1996.060.403.14
Kunzmann, Thomas (1999) The aenigmatite-rhönite mineral group. European Journal of Mineralogy, 11 (4) 743-756 doi:10.1127/ejm/11/4/0743
Localities for Dorrite
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.
Germany | |
| Blaß et al. (2015) |
| Blaß et al. (2015) |
| Kunzmann (1999) +1 other reference |
| Blaß et al. (2015) | |
| Blaß et al. (2015) |
| Shchipalkina et al. (2019) |
| Blaß et al. (2014) |
Israel | |
| Britvin et al. (2021) +1 other reference |
| Krüger et al. (2021) |
Jordan | |
| Khoury et al. (2015) +1 other reference |
Middle East | |
| Vapnik et al. (2014) | |
Mongolia | |
| Savina et al. (2020) |
Russia | |
| Cesnokov et al. (1998) |
| Shchipalkina et al. (2016) |
USA (TL) | |
| Amer.Min. (1988) |
| American Mineralogist |
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Caspar quarry, Ettringen, Vordereifel, Mayen-Koblenz, Rhineland-Palatinate, Germany