Biotite Mineral Data (original) (raw)

General Biotite Information

Help on Chemical Formula: Chemical Formula:

K(Mg,Fe++)3[AlSi3O10(OH,F)2

Help on Composition: Composition:

Molecular Weight = 433.53 gm

Potassium 9.02 % K 10.86 % K2O

Magnesium 14.02 % Mg 23.24 % MgO

Aluminum 6.22 % Al 11.76 % Al2O3

Iron 6.44 % Fe 8.29 % FeO

Silicon 19.44 % Si 41.58 % SiO2

Hydrogen 0.41 % H 3.64 % H2O

Oxygen 43.36 % O

Fluorine 1.10 % F 1.10 % F

- % F -0.46 % -O=F2

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Help on Empirical Formula: Empirical Formula:

KMg2.5Fe2+0.5AlSi3O10(OH)1.75F0.25

Help on Environment: Environment:

Granitic rocks. Forms a series with phlogopite. Has several polytypes (1M, 3T, 2M1). Biotite is now a group name for phlogopite, siderophyllite and eastonite.

Help on IMA Status: IMA Status:

Not Approved IMA 1998 - Bitote is now the group name

Help on Locality: Locality:

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

Help on Name Origin: Name Origin:

Named in 1847 after the French physicist, Jean Baptiste Biot (1774 - 1862), who studied the optical properties of the micas.

Help on Name Pronunciation: Name Pronunciation:

Biotite Say BIOTITE

Help on Synonym: Synonym:

Iron Mica

Lepidomelane (Fe)

Manganophyllite (Mn)

Micaceous Iron Ore

Oxybiotite

Biotite Image

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Biotite Crystallography

Help on Axial Ratios: Axial Ratios:

a:b:c =0.5771:1:1.1046

Help on Cell Dimensions: Cell Dimensions:

a = 5.343, b = 9.258, c = 10.227, Z = 2; beta = 100.26° V = 497.79 Den(Calc)= 2.89

Help on Crystal System: Crystal System:

Monoclinic - PrismaticH-M Symbol (2/m) Space Group: C 2/m

Help on X Ray Diffraction: X Ray Diffraction:

By Intensity(I/Io): 3.37(1), 10.1(1), 2.66(0.8),

Help on Forms: Forms:

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| | Forms:( 1 1 2) ( 2 2 1) ( 0 1 0) ( 0 0 1) Warning: this large pop-up is very compute intensive and may not work well with some computers. | | ---------------------------------------------------------------------------------------------------------------------------------------------------------------- |

Click Here for Large Biotite Structure Window Crystal Structure:

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| | Hendricks S B , Jefferson M E , American Mineralogist , 24 (1939) p.729-771, Polymorphism of the micas with optical measurements View Additional jPOWD Structure files for Biotite [1] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [2] [20] [21] [22] [23] [24] [25] [26] [27] [28] [3] [4] [5] [6] [7] [8] [9] | | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |

Physical Properties of Biotite

Help on Cleavage: Cleavage:

{001} Perfect

Help on Color: Color:

Dark brown, Greenish brown, Blackish brown, Yellow, White.

Help on Density: Density:

2.8 - 3.4, Average = 3.09

Help on Diaphaneity: Diaphaneity:

Transparent to translucent to opaque

Help on Fracture: Fracture:

Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern.

Help on Habit: Habit:

Lamellar - Thin laminae producing a lamellar structure.

Help on Habit: Habit:

Micaceous - Platy texture with "flexible" plates.

Help on Habit: Habit:

Pseudo Hexagonal - Crystals show a hexagonal outline.

Help on Hardness: Hardness:

2.5-3 - Finger Nail-Calcite

Help on Luminescence: Luminescence:

Non-fluorescent.

Help on Luster: Luster:

Vitreous - Pearly

Help on Streak: Streak:

gray

Optical Properties of Biotite

Help on Gladstone-Dale: Gladstone-Dale:

CI meas= 0.026 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.044 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2163,KPDmeas= 0.2016,KC= 0.2071
Ncalc = 1.58 - 1.7

Help on Optical Data: Optical Data:

Biaxial (-), a=1.565-1.625, b=1.605-1.675, g=1.605-1.675, bire=0.0400-0.0500, 2V(Calc)=0, 2V(Meas)=0-25. Dispersion r > v or r < v.

Help on Pleochroism (x): Pleochroism (x):

yellow, buff, light brown, pale greenish brown, or pale greenish brown.

Help on Pleochroism (y): Pleochroism (y):

reddish brown, brown, greenish brown, bluish green, or opaque.

Calculated Properties of Biotite

Help on Electron Density: Electron Density:

Bulk Density (Electron Density)=3.07 gm/cc
note: Specific Gravity of Biotite =3.10 gm/cc.

Help on Fermion Index: Fermion Index:

Fermion Index = 0.02
Boson Index = 0.98

Help on Photoelectric: Photoelectric:

PEBiotite = 4.04 barns/electron
U=PEBiotite x relectron= 12.42 barns/cc.

Help on Radioactivity: Radioactivity:

GRapi = 129.08 (Gamma Ray American Petroleum Institute Units)
Concentration of Biotite per GRapi unit = 0.77 (%)

Estimated Radioactivity from Biotite - barely detectable

Biotite Classification

Help on Dana Class: Dana Class:

71.02.02b.02 (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

Help on Strunz Class: 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 Biotite Information

Help on See Also: See Also:

Links to other databases for Biotite :
1 - Alkali-Nuts(English)
2 - Alkali-Nuts(Francais)
3 - Am. Min. Crystal Structure Database
4 - Amethyst Galleries' Mineral Gallery
5 - Athena
6 - EUROmin Project
7 - Ecole des Mines de Paris
8 - Franklin Minerals(Dunn)
9 - Franklin Minerals(Palache)
10 - GeoScienceWorld
11 - Glendale Community College
12 - Google Images
13 - Google Scholar
14 - Handbook of Mineralogy (MinSocAm)
15 - Handbook of Mineralogy (UofA)
16 - MinDAT
17 - Mineral and Gemstone Kingdom
18 - Mineralienatlas (Deutsch)
19 - Minerals in Thin Section-University of North Carolina
20 - Minerals in Thin Sections-Humboldt State
21 - Online Mineral Museum
22 - QUT Mineral Atlas
23 - Ruff.Info
24 - Scandinavian mineral gallery
25 - UCLA - Petrography Thin-Sections
26 - WWW-MINCRYST

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Ask about Biotite here :
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Print or Cut-and-Paste your Biotite Specimen Label here :

Biotite

K(Mg,Fe++)3[AlSi3O10(OH,F)2
Dana No: 71.02.02b.02 Strunz No: 09.EC.20
Locality:

Notes: