Dorrite
A valid IMA mineral species
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About Dorrite
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
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.
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