Mineralogy Database

Hydrobiotite Mineral Data

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General Hydrobiotite Information

Help on Chemical  Formula: Chemical Formula: [K(Mg,Fe)3(Al,Fe)Si3O10(OH,F)2]•[(Mg,Fe++,Al)3(Si,Al)4O10(OH)2•4(H2O)]
Help on Composition: Composition: Molecular Weight = 464.62 gm
   Potassium   2.52 %  K     3.04 % K2O
   Calcium     0.86 %  Ca    1.21 % CaO
   Magnesium  12.03 %  Mg   19.95 % MgO
   Aluminum    6.97 %  Al   13.17 % Al2O3
   Iron        7.21 %  Fe   10.31 % Fe2O3
   Silicon    16.93 %  Si   36.21 % SiO2
   Hydrogen    1.69 %  H    15.12 % H2O
   Oxygen     50.96 %  O
   Fluorine    0.82 %  F     0.82 % F
                -   %   F    -0.34 % -O=F2    
             ______        ______ 
             100.00 %       99.48 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Mg2.3Fe3+0.6K0.3Ca0.1Si2.8Al1.2O10(OH)1.8F0.2�3(H2O)
Help on Environment: Environment: Found in a wide variety of sedimentary environments.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1882
Help on Locality: Locality: Common world wide. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for the water content and its relationship to biotite.
Help on Name Pronunciation: Name Pronunciation: Hydrobiotite + Pronunciation Say HYDROBIOTITE
Help on Synonym: Synonym: Biotitic vermiculite

Hydrobiotite Image

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Comments: Silvery brown micaceous hydrobiotite.
Location: Oaxaca, Mexico. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Hydrobiotite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.5777:1:2.7222
Help on Cell Dimensions: Cell Dimensions: a = 5.2, b = 9, c = 24.5, Z = 4; beta = 90° V = 1,146.60 Den(Calc)= 2.69
Help on Crystal System: 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/Io): 12.26(1), 3.5(0.5), 3.05(0.2),23.6(0.2), 2.04(0.15), 4.88(0.15), 2.73(0.1), 8.18(0.05),

Physical Properties of Hydrobiotite

Help on Cleavage: Cleavage: {001} Perfect
Help on Color: Color: Golden yellow, Black.
Help on Density: Density: 2.49 - 2.64, Average = 2.56
Help on Diaphaneity: Diaphaneity: Translucent
Help on Fracture: Fracture: Flexible - Flexible fragments.
Help on Hardness: Hardness: 2.5-3 - Finger Nail-Calcite
Help on Luster: Luster: Sub Metallic
Help on Streak: Streak: white

Optical Properties of Hydrobiotite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.066 (Fair) - where the CI = (1-KPDmeas/KC)
CI calc= 0.11 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2095,KPDmeas= 0.2197,KC= 0.2353
Ncalc = 1.59 - 1.63
Help on Optical Data: Optical Data: Biaxial (-), b=1.56-1.562, g=1.565-1.567, , 2V(Meas)=10.
Help on Pleochroism (x): Pleochroism (x): light brown.
Help on Pleochroism (y): Pleochroism (y): brown.
Help on Pleochroism (z): Pleochroism (z): brown.

Calculated Properties of Hydrobiotite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.58 gm/cc
note: Specific Gravity of Hydrobiotite =2.57 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.02
Boson Index = 0.98
Help on Photoelectric: Photoelectric: PEHydrobiotite = 3.61 barns/electron
U=PEHydrobiotite x relectron= 9.31 barns/cc.
Help on Radioactivity: Radioactivity:

GRapi = 36.65 (Gamma Ray American Petroleum Institute Units)
Concentration of Hydrobiotite per GRapi unit = 2.73 (%)

Estimated Radioactivity from Hydrobiotite - barely detectable


Hydrobiotite Classification

Help on  Dana Class: Dana Class: 71.02.02d.01 (71)Phyllosilicate Sheets of Six-Membered Rings
  (71.02)with 2:1 Layers
  (71.02.02d)Mica Group (Hydromica subgroup)
71.02.02d.01 Hydrobiotite [K(Mg,Fe)3(Al,Fe)Si3O10(OH,F)2]•[(Mg,Fe,Al)3(Si,Al)4O10(OH)2•4(H2O)] C 2/m 2/m
71.02.02d.02 Illite* (K,H3O)(Al,Mg,Fe)2(Si,Al)4O10[(OH)2,(H2O)] C 2/m 2/m
71.02.02d.03 Vermiculite (Mg,Fe,Al)3(Al,Si)4O10(OH)2•4(H2O) C 2/m 2/m
71.02.02d.04 Brammallite* (Na,H3O)(Al,Mg,Fe)2(Si,Al)4O10[(OH)2,(H2O)] C 2/c 2/m
Help on  Strunz Class: Strunz Class: 09.EC.60 09 - SILICATES (Germanates)
  09.E - Phyllosilicates
  09.EC -Phyllosilicates with mica sheets, composed of tetrahedral and octahedral nets
09.EC.60 Aliettite [Mg3Si4O10(OH)2](Ca0.5,Na)0.33(Al,Mg,Fe)2-3(Si,Al)4O10(OH)2•n(H2O) Unk Mono
09.EC.60 Dozyite (Mg7Al2)(Si4Al2)O15(OH)12 Cm m
09.EC.60 Corrensite (Ca,Na,K)(Mg,Fe,Al)9(Si,Al)8O20(OH)10•n(H2O) Unk Ortho
09.EC.60 Kulkeite Na0.35Mg8AlSi7O20(OH)10 Unk Mono
09.EC.60 Karpinskite (Mg,Ni)2Si2O5(OH)2(?) Unk Mono
09.EC.60 Illite* (K,H3O)(Al,Mg,Fe)2(Si,Al)4O10[(OH)2,(H2O)] C 2/m 2/m
09.EC.60 Hydrobiotite [K(Mg,Fe)3(Al,Fe)Si3O10(OH,F)2]•[(Mg,Fe,Al)3(Si,Al)4O10(OH)2•4(H2O)] C 2/m 2/m
09.EC.60 Lunijianlaite LiAl6(Si7Al)O20(OH)10 Unk Mono
09.EC.60 Rectorite (Na,Ca)Al4(Si,Al)8O20(OH)4•2(H2O) Unk Mono
09.EC.60 Saliotite Na0.5Li0.5Al3AlSi3O10(OH)5 C 2/m 2/m
09.EC.60 Tosudite Na0,5(Al,Mg)6(Si,Al)8O18(OH)12•5(H2O) Unk Ortho
09.EC.60 Brinrobertsite! (Na,K,Ca)x(Al,Fe,Mg)4(Si,Al)8O20(OH)4•3.54(H2O)[x=0.35,n=3.54] pseudo 2/m 2/m

Other Hydrobiotite Information

Help on References: References: NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Dana8)
Help on See Also: See Also: Links to other databases for Hydrobiotite :
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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Dana No: 71.02.02d.01 Strunz No: 09.EC.60





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