Tetraferriannite Mineral Data

General Tetraferriannite Information

Chemical Formula:

K(Fe++,Mg)3(Fe+++,Al)Si3O10(OH)2

Composition:

Molecular Weight = 517.76 gm

Potassium 7.55 % K 9.10 % K₂O

Magnesium 2.35 % Mg 3.89 % MgO

Aluminum 1.30 % Al 2.46 % Al₂O₃

Iron 35.06 % Fe 34.69 % FeO / 11.57 % Fe₂O₃

Silicon 16.27 % Si 34.81 % SiO₂

Hydrogen 0.39 % H 3.48 % H₂O

Oxygen 37.08 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

KFe²⁺_2.5Mg_0.5Fe³⁺_0.75Al_0.25Si₃O₁₀(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

Ferriannite

Ferribiotite

Monrepite

Tetra-ferri-annite - Renamed Tetraferriannite by Mineralogical Record, v39 (2008), p131

Tetraferriannite Image

Images:

Tetraferriannite

Comments: Brownish black crystal fragment of tetraferriannite showing the micaceous cleavage.
Location: Bancroft District, Hastings Co., Ontario, Canada. Scale: Sample Size 1 cm.
© Jeff Weissman / Photographic Guide to Mineral Species

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 - Prismatic H-M Symbol (2/m) Space Group: C 2/m

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 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),

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:

PE_{Tetraferriannite}= 11.93 barns/electron
U=PE_{Tetraferriannite} x r_electron= 39.49 barns/cc.

Radioactivity:

GRapi = 106.37 (Gamma Ray American Petroleum Institute Units)
Concentration of Tetraferriannite per GRapi unit = 0.94 (%)

Estimated Radioactivity from Tetraferriannite - barely detectable

Tetraferriannite Classification

Dana Class:

71.02.02b.04 (71)Phyllosilicate Sheets of Six-Membered Rings

(71.02)with 2:1 Layers

(71.02.02b)Mica Group (Biotite subgroup)

71.02.02b.01 Phlogopite KMg3(Si3Al)O10(F,OH)2 C 2/m 2/m

71.02.02b.01a Tetraferriphlogopite! KMg3FeSi3O10(OH)2 2/m

71.02.02b.01b Shirozulite! KMn3(AlSi3)O10(OH,F)2 C 2/m 2/m

71.02.02b.01c Fluorophlogopite! KMg3(AlSi3)O10F2 C 2/m 2/m

71.02.02b.02 Biotite* K(Mg,Fe)3[AlSi3O10(OH,F)2 C 2/m 2/m

71.02.02b.03 Annite KFe3AlSi3O10(OH,F)2 C 2/m 2/m

71.02.02b.03a Fluorannite! KFe3AlSi3O10F2 C 2/m 2/m

71.02.02b.04 Tetraferriannite K(Fe,Mg)3(Fe,Al)Si3O10(OH)2 C 2/m 2/m

71.02.02b.05 Siderophyllite KFe2Al(Al2Si2)O10(F,OH)2 C 2/m 2/m

71.02.02b.05a Eastonite! KMg2Al[Al2Si2O10](OH)2 2/m

71.02.02b.06 Hendricksite K(Zn,Mg,Mn)3Si3AlO10(OH)2 C 2/m 2/m

71.02.02b.07 Lepidolite K(Li,Al)3(Si,Al)4O10(F,OH)2 C 2/m,Cm Mono

71.02.02b.08 Polylithionite KLi2AlSi4O10(F,OH)2 C 2/m 2/m

71.02.02b.08a Trilithionite! KLi1.5Al1.5AlSi3O10F2 C 2/m 2/m

71.02.02b.08b Sokolovaite! CsLi2AlSi4O10F2 C 2/m, C 2 or Cm Mono

71.02.02b.09 Tainiolite KLiMg2Si4O10F2 C 2/m 2/m

71.02.02b.10 Zinnwaldite KLiFeAl(AlSi3)O10(F,OH)2 C 2/m 2/m

71.02.02b.11 Norrishite K(Mn2Li)Si4O10(O)2 C 2/m 2/m

71.02.02b.12 Masutomilite K(Li,Al,Mn)3[(Si,Al)4O10](F,OH)2 C 2/m 2/m

71.02.02b.13 Aspidolite NaMg3AlSi3O10(OH)2 C 2/m 2/m

71.02.02b.14 Wonesite (Na,K).5(Mg,Fe,Al)3(Si,Al)4O10(OH,F)2 C 2/m 2/m

71.02.02b.15 Preiswerkite NaMg2Al3Si2O10(OH)2 C 2/m 2/m

71.02.02b.16 Ephesite NaLiAl2(Al2Si2)O10(OH)2 C 2/c 2/m

71.02.02b.18 Suhailite! (NH4)Fe3(Si3Al)O10(OH)2 C 2/m? 2/m

Strunz Class:

09.EC.20 09 - SILICATES (Germanates)

09.E - Phyllosilicates

09.EC -Phyllosilicates with mica sheets, composed of tetrahedral and octahedral nets

09.EC.20 Annite KFe3AlSi3O10(OH,F)2 C 2/m 2/m

09.EC.20 Biotite* K(Mg,Fe)3[AlSi3O10(OH,F)2 C 2/m 2/m

09.EC.20 Hendricksite K(Zn,Mg,Mn)3Si3AlO10(OH)2 C 2/m 2/m

09.EC.20 Ephesite NaLiAl2(Al2Si2)O10(OH)2 C 2/c 2/m

09.EC.20 Aspidolite NaMg3AlSi3O10(OH)2 C 2/m 2/m

09.EC.20 Lepidolite K(Li,Al)3(Si,Al)4O10(F,OH)2 C 2/m,Cm Mono

09.EC.20 Preiswerkite NaMg2Al3Si2O10(OH)2 C 2/m 2/m

09.EC.20 Masutomilite K(Li,Al,Mn)3[(Si,Al)4O10](F,OH)2 C 2/m 2/m

09.EC.20 Wonesite (Na,K).5(Mg,Fe,Al)3(Si,Al)4O10(OH,F)2 C 2/m 2/m

09.EC.20 Polylithionite KLi2AlSi4O10(F,OH)2 C 2/m 2/m

09.EC.20 Phlogopite KMg3(Si3Al)O10(F,OH)2 C 2/m 2/m

09.EC.20 Norrishite K(Mn2Li)Si4O10(O)2 C 2/m 2/m

09.EC.20 Siderophyllite KFe2Al(Al2Si2)O10(F,OH)2 C 2/m 2/m

09.EC.20 Fluorannite! KFe3AlSi3O10F2 C 2/m 2/m

09.EC.20 Shirokshinite! K(NaMg2)Si4O10F2 C 2/m 2/m

09.EC.20 Zinnwaldite KLiFeAl(AlSi3)O10(F,OH)2 C 2/m 2/m

09.EC.20 Eastonite! KMg2Al[Al2Si2O10](OH)2 2/m

09.EC.20 Tetraferriannite K(Fe,Mg)3(Fe,Al)Si3O10(OH)2 C 2/m 2/m

09.EC.20 Tetraferriphlogopite! KMg3FeSi3O10(OH)2 2/m

09.EC.20 Trilithionite! KLi1.5Al1.5AlSi3O10F2 C 2/m 2/m

09.EC.20 Sokolovaite! CsLi2AlSi4O10F2 C 2/m, C 2 or Cm Mono

09.EC.20 Shirozulite! KMn3(AlSi3)O10(OH,F)2 C 2/m 2/m

09.EC.20 Suhailite! (NH4)Fe3(Si3Al)O10(OH)2 C 2/m? 2/m

09.EC.20 Fluorophlogopite! KMg3(AlSi3)O10F2 C 2/m 2/m

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

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Print or Cut-and-Paste your Tetraferriannite Specimen Label here :

Tetraferriannite

K(Fe++,Mg)3(Fe+++,Al)Si3O10(OH)2
Dana No: 71.02.02b.04 Strunz No: 09.EC.20
Locality:

Notes:

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