General Tetraferriannite Information Chemical Formula: |
K(Fe++,Mg)3(Fe+++,Al)Si3O10(OH)2 |
Composition: |
Molecular Weight = 517.76 gm |
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Potassium 7.55 % K 9.10 % K2O |
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Magnesium 2.35 % Mg 3.89 % MgO |
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Aluminum 1.30 % Al 2.46 % Al2O3 |
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Iron 35.06 % Fe 34.69 % FeO / 11.57 % Fe2O3 |
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Silicon 16.27 % Si 34.81 % SiO2 |
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Hydrogen 0.39 % H 3.48 % H2O |
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Oxygen 37.08 % O |
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______ ______ |
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100.00 % 100.00 % = TOTAL OXIDE |
Empirical Formula: |
KFe2+2.5Mg0.5Fe3+0.75Al0.25Si3O10(OH)2 |
Environment: |
Metamorphosed banded-iron formation. |
IMA Status: |
Renamed IMA 1998 Formerly ferri-annite |
Locality: |
Dales George member, Hammersley group, Wittenoom, WA, Australia. Link to MinDat.org Location Data. |
Name Origin: |
Named in 1963 for the composition and relationship to annite. Renamed to Tetra-ferri-annite. |
Synonym: |
Ferri-annite |
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Ferriannite |
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Ferribiotite |
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Monrepite |
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Tetra-ferri-annite - Renamed Tetraferriannite by Mineralogical Record, v39 (2008), p131 |
| | Tetraferriannite Image
Images:
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Tetraferriannite Crystallography Axial Ratios: |
a:b:c =0.5848:1:1.1157 |
Cell Dimensions: |
a = 5.402, b = 9.237, c = 10.306, Z = 2; beta = 99.267° V = 507.54 Den(Calc)= 3.39 |
Crystal System: |
Monoclinic - PrismaticH-M Symbol (2/m) Space Group: C 2/m |
X Ray Diffraction: |
By Intensity(I/Io): 10.159(1), 1.696(0.5), 3.684(0.5),3.379(0.5), 1.66(0.3), 1.539(0.1), 2.67(0.1), 2.91(0.1), |
Crystal Structure:
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Mouse
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| Physical Properties of Tetraferriannite Cleavage: |
{001} Perfect |
Color: |
Brown, Brownish black. |
Density: |
2.7 - 3.4, Average = 3.05 |
Diaphaneity: |
Transparent to Opaque |
Habit: |
Massive - Lamellar - Distinctly foliated fine-grained forms. |
Habit: |
Scaly - Morphology like fish scales. |
Hardness: |
2.5-3 - Finger Nail-Calcite |
Luster: |
Vitreous - Adamantine |
Streak: |
light brown |
| Optical Properties of Tetraferriannite Gladstone-Dale: |
CI meas= -0.064 (Fair) - where the CI = (1-KPDmeas/KC) |
CI calc= 0.043 (Good) - where the CI = (1-KPDcalc/KC) KPDcalc= 0.2073,KPDmeas= 0.2304,KC= 0.2166 Ncalc = 1.58 - 1.74 Optical Data: |
Biaxial (-), a=1.66, b=1.72, g=1.728, bire=0.0680 |
| Calculated Properties of Tetraferriannite Electron Density: |
Bulk Density (Electron Density)=3.31 gm/cc |
note: Specific Gravity of Tetraferriannite =3.39 gm/cc. Fermion Index: |
Fermion Index = 0.01 |
Boson Index = 0.99 Photoelectric: |
PETetraferriannite = 11.93 barns/electron |
U=PETetraferriannite x relectron= 39.49 barns/cc. Radioactivity: |
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GRapi = 106.37 (Gamma Ray American Petroleum Institute Units)
Estimated Radioactivity from Tetraferriannite - barely detectable | Tetraferriannite Classification Dana Class: |
71.02.02b.04 (71)Phyllosilicate Sheets of Six-Membered Rings |
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(71.02)with 2:1 Layers |
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(71.02.02b)Mica Group (Biotite subgroup) |
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Strunz Class: |
09.EC.20 09 - SILICATES (Germanates) |
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09.E - Phyllosilicates |
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09.EC -Phyllosilicates with mica sheets, composed of tetrahedral and octahedral nets |
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| Other Tetraferriannite Information References: |
NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Dana8) |
See Also: |
Links to other databases for Tetraferriannite : |
1 - Am. Min. Crystal Structure Database 2 - Athena 3 - GeoScienceWorld 4 - Google Images 5 - Google Scholar 6 - MinDAT 7 - Mineralienatlas (Deutsch) 8 - Online Mineral Museum 9 - QUT Mineral Atlas 10 - Ruff.Info Search for Tetraferriannite using: Visit our Advertisers for Tetraferriannite : A Bijoux Google Search for TetraferrianniteAdam's Minerals Google Search for Tetraferriannite Cape Minerals Google Search for Tetraferriannite Dakota Matrix Minerals Google Search for Tetraferriannite Excalibur Mineral Corp. Google Search for Tetraferriannite Exceptional Minerals Google Search for Tetraferriannite John Betts Fine Minerals Search for Tetraferriannite McDougall Minerals Google Search for Tetraferriannite Mineral News Website Link Rock and Mineral Shows Google Search for Tetraferriannite Weinrich Minerals, Inc. Google Search for Tetraferriannite Ask about Tetraferriannite here : Print or Cut-and-Paste your Tetraferriannite Specimen Label here :
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