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Dorrite Mineral Data
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General Dorrite Information
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 Chemical Formula: |
Ca2Mg2Fe+++4(Al,Fe+++)4Si2O20 |
| Composition: |
Molecular Weight = 893.97 gm |
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Calcium 8.97 % Ca 12.55 % CaO |
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Magnesium 5.44 % Mg 9.02 % MgO |
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Aluminum 6.04 % Al 11.41 % Al2O3 |
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Iron 37.48 % Fe 53.59 % Fe2O3 |
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Silicon 6.28 % Si 13.44 % SiO2 |
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Oxygen 35.79 % O |
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______ ______ |
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100.00 % 100.00 % = TOTAL OXIDE |
| Empirical Formula: |
Ca2Mg2Fe3+6Al2Si2O20 |
| Environment: |
Occurs in a paralava (pyrometamorhic melt rock) formed from burning coal beds. |
| IMA Status: |
Approved IMA 1988 |
| Locality: |
Druham ranch, 25 km S of Gillette in the Powder River Basin, Wyoming. USA. Link to MinDat.org Location Data. |
| Name Origin: |
Named for John A. Dorr (1922-1986), University of Michigan. |
| Name Pronunciation: |
Dorrite  |
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Dorrite Image |
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Images:
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Dorrite Crystallography
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| Axial Ratios: |
a:b:c =0.964:1:0.8276 |
| Cell Dimensions: |
a = 10.505, b = 10.897, c = 9.019, Z = 2; alpha = 106.26°, beta = 95.16°, gamma = 124.75° V = 811.06 Den(Calc)= 3.66 |
| Crystal System: |
Triclinic Space Group: P1,P 1 |
| X Ray Diffraction: |
By Intensity(I/Io): 2.971(1), 2.515(0.8), 2.558(0.8), |
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Physical Properties of Dorrite
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| Cleavage: |
{001} Distinct, {010} Distinct |
| Color: |
Brownish black, Dark brown, Reddish brown. |
| Diaphaneity: |
Subopaque |
| Fracture: |
Irregular - Flat surfaces (not cleavage) fractured in an irregular pattern. |
| Habit: |
Anhedral Grains - Granular minerals without the expression of crystal shapes |
| Habit: |
Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline). |
| Hardness: |
5 - Apatite |
| Luster: |
Sub Metallic |
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Optical Properties of Dorrite
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| Gladstone-Dale: |
CI calc= 0.174 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2188,KC= 0.2648
Ncalc = 2.02 |
| Optical Data: |
Biaxial (-), a=1.82, b=1.84, g=1.86, bire=0.0400, 2V(Calc)=88, 2V(Meas)=90. |
| Pleochroism (x): |
red-orange brown. |
| Pleochroism (y): |
yellowish brown. |
| Pleochroism (z): |
greenish brown. |
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Calculated Properties of Dorrite
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| Electron Density: |
Bulk Density (Electron Density)=3.73 gm/cc
note: Specific Gravity of Dorrite =3.84 gm/cc.
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| Fermion Index: |
Fermion Index = 0.01
Boson Index = 0.99 |
| Photoelectric: |
PEDorrite = 12.91 barns/electron
U=PEDorrite x rElectron Density= 48.12 barns/cc.
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| Radioactivity: |
GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Dorrite is Not Radioactive |
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Dorrite Classification
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| Dana Class: |
69.02.01a.02 (69)Inosilicate Chains with Side Branches or Loops |
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(69.02)with P>2 |
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(69.02.01a)Aenigmatite and related species (Aenigmatite subgroup) |
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69.02.01a.01 Aenigmatite (Na,Ca)4(Fe,Ti,Mg)12Si12O40 P1 1 |
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69.02.01a.02 Dorrite Ca2Mg2Fe4(Al,Fe)4Si2O20 P1,P 1 Tri |
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69.02.01a.03 Hogtuvaite (Ca,Na)2(Fe,Fe,Ti,Mg,Mn)6(Si,Be,Al)6O20 P1 1 |
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69.02.01a.04 Krinovite NaMg2CrSi3O10 P1 1 |
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69.02.01a.05 Rhonite Ca2(Mg,Fe,Fe,Ti)6(Si,Al)6O20 P1 1 |
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69.02.01a.06 Serendibite Ca2(Mg,Al)6(Si,Al,B)6O20 P1 1 |
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69.02.01a.07 Welshite Ca4Mg9Sb3O4[Si6Be3AlFe2O36] P1 1 |
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69.02.01a.08 Wilkinsonite Na2Fe4Fe2Si6O20 P1 1 |
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69.02.01a.09 Makarochkinite! Ca2Fe4FeTiSi4BeAlO20 P1 1 |
| Strunz Class: |
09.DH.45 09 - SILICATES (Germanates) |
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09.D - Inosilicates* Structural terminology according to Liebau (1985) |
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09.DH -Inosilicates with 4-periodic single chains, Si4O12 |
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09.DH.45 Aenigmatite (Na,Ca)4(Fe,Ti,Mg)12Si12O40 P1 1 |
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09.DH.45 Dorrite Ca2Mg2Fe4(Al,Fe)4Si2O20 P1,P 1 Tri |
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09.DH.45 Krinovite NaMg2CrSi3O10 P1 1 |
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09.DH.45 Rhonite Ca2(Mg,Fe,Fe,Ti)6(Si,Al)6O20 P1 1 |
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09.DH.45 Sapphirine (Mg,Al)8(Al,Si)6O20 P1 1 |
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09.DH.45 Serendibite Ca2(Mg,Al)6(Si,Al,B)6O20 P1 1 |
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09.DH.45 Khmaralite! (Mg,Al,Fe)16(Al,Si,Be)12O40 P 21/c 2/m |
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09.DH.45 Makarochkinite! Ca2Fe4FeTiSi4BeAlO20 P1 1 |
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09.DH.45 Welshite Ca4Mg9Sb3O4[Si6Be3AlFe2O36] P1 1 |
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09.DH.45 Wilkinsonite Na2Fe4Fe2Si6O20 P1 1 |
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Other Dorrite Information
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| References: |
NAME( Dana8) PHYS. PROP.(Dana8) OPTIC PROP.(Dana8) |
| See Also: |
Links to other databases for Dorrite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - GeoScienceWorld
6 - Google Images
7 - Google Scholar
8 - Handbook of Mineralogy (MinSocAm)
9 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info
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Print or Cut-and-Paste your Dorrite Specimen Label here :
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Dorrite
Ca2Mg2Fe+++4(Al,Fe+++)4Si2O20
Dana No: 69.02.01a.02 Strunz No: 09.DH.45
Locality:
Notes:
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