Hydrobiotite Mineral Data

General Hydrobiotite Information

Chemical Formula:

[K(Mg,Fe)3(Al,Fe)Si3O10(OH,F)2]•[(Mg,Fe++,Al)3(Si,Al)4O10(OH)2•4(H2O)]

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

Empirical Formula:

Mg_2.3Fe³⁺_0.6K_0.3Ca_0.1Si_2.8Al_1.2O₁₀(OH)_1.8F_0.2ï¿½3(H₂O)

Environment:

Found in a wide variety of sedimentary environments.

IMA Status:

Valid Species (Pre-IMA) 1882

Locality:

Common world wide. Link to MinDat.org Location Data.

Name Origin:

Named for the water content and its relationship to biotite.

Name Pronunciation:

Hydrobiotite + Pronunciation

Synonym:

Biotitic vermiculite

Hydromica

Jefferisite

Hydrobiotite Image

Images:

Hydrobiotite

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

Hydrobiotite Crystallography

Axial Ratios:

a:b:c =0.5777:1:2.7222

Cell Dimensions:

a = 5.2, b = 9, c = 24.5, Z = 4; beta = 90° V = 1,146.60 Den(Calc)= 2.69

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): 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

Cleavage:

{001} Perfect

Color:

Golden yellow, Black.

Density:

2.49 - 2.64, Average = 2.56

Diaphaneity:

Translucent

Fracture:

Flexible - Flexible fragments.

Hardness:

2.5-3 - Finger Nail-Calcite

Luster:

Sub Metallic

Streak:

white

Optical Properties of Hydrobiotite

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

Optical Data:

Biaxial (-), b=1.56-1.562, g=1.565-1.567, , 2V(Meas)=10.

Pleochroism (x):

light brown.

Pleochroism (y):

brown.

Pleochroism (z):

brown.

Calculated Properties of Hydrobiotite

Electron Density:

Bulk Density (Electron Density)=2.58 gm/cc
note: Specific Gravity of Hydrobiotite =2.57 gm/cc.

Fermion Index:

Fermion Index = 0.02
Boson Index = 0.98

Photoelectric:

PE_Hydrobiotite= 3.61 barns/electron
U=PE_Hydrobiotite x r_electron= 9.31 barns/cc.

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

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

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

References:

NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Dana8)

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

Hydrobiotite

[K(Mg,Fe)3(Al,Fe)Si3O10(OH,F)2]•[(Mg,Fe++,Al)3(Si,Al)4O10(OH)2•4(H2O)]
Dana No: 71.02.02d.01 Strunz No: 09.EC.60
Locality:

Notes:

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