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About BiotiteHide

Jean Baptiste Biot [April 21, 1774 Paris, France - February 3, 1862 Paris, France]
Approximated formula based on common species regarded as 'biotite'. A slash in the formula indicates different elements can occur in this position but without assumption on priority.
Named in 1847 by Johann Friedrich Ludwig Hausmann in honour of the French physicist, mathematician, meteoriticist, astronomer, and mineralogist, Jean-Baptiste Biot [April 21, 1774, Paris, France - February 3, 1862, Paris, France], who studied the optical properties of the micas. Biot and his associate, Félix Savart, discovered that an electric current in a wire produced a magnetic field. Biot received many awards in his lifetime in recognition of the value of his scientific researches.
A series or subgroup of the Mica Group.

The CNMMN Subcommittee on Nomenclature of the Micas (1998, 1999) has recommended that the name biotite be used for a series between the joins Annite-Phlogopite and Siderophyllite-Eastonite, and is therefore no longer to be regarded as a species name. Fluorophlogopite and Fluorotetraferriphlogopite should be included. The name is most commonly used for the micas on the Fe-rich end of the series, including Annite, Fluorannite, Tetra-ferri-annite and Siderophyllite.

The name "biotite" is also used as a generic field term for any incompletely analysed dark mica.

May alter to vermiculite.

Rock-forming biotite may be confused with stilpnomelane.

Classification of BiotiteHide

Redefined by the IMA

Pronounciation of BiotiteHide

PlayRecorded byCountry
Jolyon & Katya RalphUnited Kingdom

Chemical Properties of BiotiteHide


Approximated formula based on common species regarded as 'biotite'. A slash in the formula indicates different elements can occur in this position but without assumption on priority.

Age distributionHide

Recorded ages:
Paleoarchean to Quaternary : 3366 Ma to 1.34 ± 0.05 Ma - based on 224 recorded ages.

Crystallographic forms of BiotiteHide

Crystal Atlas:
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Biotite no.7 - Goldschmidt (1913-1926)
3d models and HTML5 code kindly provided by

Edge Lines | Miller Indices | Axes

Opaque | Translucent | Transparent

Along a-axis | Along b-axis | Along c-axis | Start rotation | Stop rotation

X-Ray Powder DiffractionHide

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Radiation - Copper Kα
Data Set:
Data courtesy of RRUFF project at University of Arizona, used with permission.

Synonyms of BiotiteHide

Other Language Names for BiotiteHide

Simplified Chinese:黑云母

Varieties of BiotiteHide

AnomiteMica group. An anomalous (hence the name) variety of "biotite" which has its optic axial plane perpendicular to (010).
Barian-Titanian BiotiteA barium- and titanium-bearing biotite mica.
Chrom-BiotitA Cr-bearing variety of biotite.
Chromian BiotiteA Cr-bearing variety of biotite.
Eastonite (of Winchell)A name for the Biotite end-member.
HeterophylliteDesignation for a uniaxial biotite from Mangualde, Portugal.
ManganophylliteA Mn-rich variety of Biotite.
Mg(T) MicaAn Aluminium-poor Biotite group mica.
NatronbiotiteA biotite with Na partially replacing K
OxybiotiteAn oxidized biotite (?). Name not mentioned in the mica report.
RubellanOxidized and dehydrogenated Biotite.
TitanbiotiteTi-bearing variety of biotite; occurs in volcanic rocks.
Titanian BiotiteTi variety of Biotite

Relationship of Biotite to other SpeciesHide

Other Members of this group:
AspidoliteNaMg3(AlSi3O10)(OH)2Mon. 2/m : B2/m
BalestraiteKLi2V5+Si4O12Mon. 2 : B2
HendricksiteK(Zn,Mg,Mn2+)3(AlSi3O10)(OH)2Mon. 2/m : B2/m
LepidoliteA Li-rich mica in, or close to, the so-called Polylithionite-Trilithionite series.Mon.
NorrishiteKLiMn3+2(Si4O10)O2Mon. 2/m : B2/m
PolylithioniteKLi2Al(Si4O10)(F,OH)2Mon. 2/m : B2/b
ShirozuliteK(Mn2+,Mg)3(AlSi3O10)(OH)2Mon. 2/m : B2/m
Suhailite(NH4)Fe2+3(AlSi3O10)(OH)2Mon. 2/m : B2/m
TrilithioniteK(Li1.5Al1.5)(AlSi3O10)(F,OH)2Mon. 2/m : B2/b
Wonesite(Na,K)(Mg,Fe,Al)6((Al,Si)4O10)2(OH,F)4Mon. 2/m : B2/m
ZinnwalditeMica Group.
Group Members:
Annite KFe2+3(AlSi3O10)(OH)2Mon. 2/m : B2/m
Eastonite KMg2Al(Al2Si2O10)(OH)2Mon.
Fluorannite KFe2+3(AlSi3O10)(F,OH)2Mon.
Fluorophlogopite KMg3(AlSi3O10)(F,OH)2Mon. 2/m : B2/m
Fluorotetraferriphlogopite KMg3(Fe3+Si3O10)F2Mon. 2/m : B2/m
Oxyphlogopite K(Mg,Ti,Fe)3[(Si,Al)4O10](O,F)2Mon. 2/m : B2/m
Phlogopite KMg3(AlSi3O10)(OH)2Mon. 2/m : B2/m
Siderophyllite KFe2+2Al(Al2Si2O10)(OH)2Mon.
Tetraferriannite KFe2+3((Fe3+,Al)Si3O10)(OH)2Mon.
Tetraferriphlogopite KMg3(Fe3+Si3O10)(OH,F)2

Other InformationHide

Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

Biotite in petrologyHide

An essential component of rock names highlighted in red, an accessory component in rock names highlighted in green.

References for BiotiteHide

Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
Parry, W.T. and Nackowski, M.P. (1963) Copper, lead, and zinc in biotites from Basin and Range quartz monzonites. Economic Geology: 58: 1126-1144.
Wones, D.R. and Eugster, H.P. (1965) Stability of biotite: experiment, theory and application. American Mineralogist: 50: 1228-1272.
Dodge, F.C.W., Smith, V.C., and May, R.E. (1969) Biotites from the granitic rocks of the central Sierra Nevada batholith. Journal of Petrology: 10: 250-271.
Lovering, T.G., Cooper, J.R., Drewes, H.D., and Cone, G.C. (1970) Copper in biotite from igneous rocks in southern Arizona as an ore indicator. USGS Professional Paper 700-B: 1-8.
Giardini, A.A., Hurst, V.J., Melton, C.E., John, C., and Stormer, J. (1974) Biotite as a primary inclusion in diamond: Its nature and significance. American Mineralogist: 59: 783-789.
Kesler, S.E., Issigonis, M.J., Brownlow, A.H., Damon, P.E., Moore, W.J., Northcote, K.E., and Preto, V.A. (1975) Geochemistry of biotites from mineralized and barren intrusive systems. Economic Geology: 70: 559-567.
Rehrig, W.A. and McKinney, C.N. (1976) The distribution and origin of anomalous copper in biotite. Mining Engineering: 27, 68 pp.
Tulloch, A. (1979) Secondary Ca-Al silicates as low-grade alteration products of granitoid biotite. Contributions to Mineralogy & Petrology: 69: 105-117.
Neiva, A. (1981) Geochemistry of hybrid granitoid rocks and of their biotites from Central Northern Portugal and their petrogenesis. Lithos: 14: 149-163.
Ohta, T., Takeda, H., and Takéuchi, Y. (1982) Mica polytypism: similarities in the crystal structures of coexisting 1M and 2M 1 oxybiotite. American Mineralogist: 67: 298-310.
Dymek, R.F. (1983) Titanium, aluminium and interlayer cation substitution in biotite from high-grade gneisses, West Greenland. American Mineralogist: 68: 880-899.
Banfield, J.F. and Eggleton, R.A. (1988) Transmission electron microscope study of biotite weathering. Clays and Clay Minerals: 36: 47-60.
Walmsley, J.C. and Lang, A.R. (1992) Oriented biotite inclusions in diamond coat. Mineralogical Magazine: 56: 108-111.
Abdel-Rahman, M.A. (1994) Nature of biotites from alkaline, calc-alkaline and peraluminous magmas. Journal of Petrology: 35: 525-541.
Nijland, T., Verschure, R. and Maijler, C. (1994) Catalytic effect of biotite: formation of hydrogarnet lenses. Comptes Rendus de l'Académie des Sciences (Paris): 318: 501-506.
Rieder, M., Cavazzani, G., D'Yakonov, Y.S., Frank-Kamenetskii, V.A., Gottardi, G., Guggenheim, S., Koval, P.V., Müller, G., Neiva, A.M.R., Radaslovich, E.W., Robert, J.-L., Sassi, F.P., Takeda, H., Weiss, Z., and Wones, D.R. (1998) Nomenclature of the micas. The Canadian Mineralogist: 36: 905-912. (
Rieder, M., Cavazzani, G., D'Yakonov, Y.S., Frank-Kamenetskii, V.A., Gottardi, G., Guggenheim, S., Koval, P.V., Müller, G., Neiva, A.M.R., Radaslovich, E.W., Robert, J.-L., Sassi, F.P., Takeda, H., Weiss, Z., and Wones, D.R.(1999) Nomenclature of the Micas. Mineralogical Magazine: 63: 267-267.
Li, G., Peacor, D.R., and Essene, E.J. (1998) The formation of sulfides during alteration of biotite to chlorite-corrensite. Clays and Clay Minerals: 46: 649-657.
Ibhi, A. and Nachit, H (2000) The substitution mechanism of Ba and Ti into phyllosilicate phases: the example of barium-titanium biotite. Annals of Chim. Sci. Mat. 25, 627-634.
Parry, W.T., Wilson, P.N., Moser, D., and Heizler, M.T. (2001) U-Pb dating of zircon and 40Ar/39Ar dating of biotite at Bingham, Utah. Economic Geology: 96: 1671-1683.
Shabani, A. and Lalonde, E. (2003) Composition of biotite from granitic rocks of the Canadian Appalachian orogen: a potential tectonomagmatic indicator? Canadian Mineralogist: 41: 1381-1396.
Machev, P., Klain, L., and Hecht, L. (2004) Mineralogy and chemistry of biotites from the Belogradchik pluton - some petrological implications for granitoid magmatism in north-west Bulgaria. Bulgarian Geological Society conference paper, Annual Scientific Conference “Geology 2004”, pp. 48-50. (

Internet Links for BiotiteHide

Significant localities for BiotiteHide

Showing 18 significant localities out of 12,752 recorded on

This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.

Locality ListHide

- This locality has map coordinates listed. - This locality has estimated coordinates. ⓘ - Click for further information on this occurrence. ? - Indicates mineral may be doubtful at this locality. - Good crystals or important locality for species. - World class for species or very significant. (TL) - Type Locality for a valid mineral species. (FRL) - First Recorded Locality for everything else (eg varieties). Struck out - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (eg from pseudomorphs.)

All localities listed without proper references should be considered as questionable.
  • Western Australia
    • Ashburton Shire
[Tetraferriannite] Miyano, T., Klein, C. (1983): Conditions of Reibeckite Formation In The Iron Formation Of The Dales Gorge Member, Hamersley Group, Western Australia, American Mineralogist (1983): 68: 517-529
  • Québec
    • Abitibi-Témiscamingue
      • La Vallée-de-l'Or RCM
        • Réservoir-Dozois
Olivier Langelier Collection
  • Inner Mongolia
    • Baotou League (Baotou Prefecture)
      • Bayan Obo mining district
        • Bayan Obo
          • Bayan Obo deposit (Bayun-Obo deposit; Baiyunebo deposit)
[Fluorotetraferriphlogopite] Miyawaki, R.,Shimazaki, H.,Shigeoka, M., Yokoyama, K.,Matsubara, S.,Yurimoto, H., Yang, Z., Zhang, P., Inoue, A., Kogure, T. and Jige, M.(2011): Fluorokinoshitalite and fluorotetraferriphlogopite; new species of fluoro-mica from Bayan Obo, Inner Mongolia, China. Clay Science. 15 (1), 13-18. ; Miyawaki R, Shimazaki H, Shigeoka M, Yokoyama K, Matsubara S, Yurimoto H (2011) Yangzhumingite, KMg2.5Si4O10F2, a new mineral in the mica group from Bayan Obo, Inner Mongolia, China. European Journal of Mineralogy 23, 467-473
  • Jiangsu
    • Suzhou
      • Suzhou City
[Fluorannite] Shen Ganfu, Lu Qi, and Xu Jinsha (2000): Acta Petrologica et Mineralogica 19(4), 356-362.
  • Rhineland-Palatinate
    • Mayen-Koblenz
      • Bell
[Oxyphlogopite] Chukanov N.V. et al.: Oxyphlogopite, K(Mg,Ti,Fe)3[(Si,Al)4O10](O,F)2, a new mica-group mineral // Zapiski RMO (in press).
  • Sicily
    • Metropolitan City of Catania
      • Etna Volcanic Complex
        • Biancavilla
[Fluorophlogopite] Antonio Gianfagna, Fernando Scordari, Simona Mazziotti-Tagliani, Gennaro Ventruti, and Luisa Ottolini (2007) Fluorophlogopite from Biancavilla (Mt. Etna, Sicily, Italy): Crystal structure and crystal chemistry of a new F-dominant analog of phlogopite. American Mineralogist, Volume 92, pages 1601–1609. - Sicurella, G., Ciriotti, M.E., Gianfagna, A., Mazziotti-Tagliani, S., Blass, G. (2010): Minerali di Monte Calvario, Biancavilla (Catania, Sicilia). Micro (località), 2/2010, 329-368.
  • Murmansk Oblast
    • Kovdor Massif
[Tetraferriphlogopite] World of Stones 95: 5-6, 64.; Rimskaya-Korsakova O.M. and Sokolova E.P. (1964) ZVMO, 93(4), p.411 (in Rus.).; Jambor, J.L. and Roberts, A.C. (2001) New mineral names. American Mineralogist: 86: 197-200.
  • Värmland County
    • Filipstad
      • Persberg ore district
        • Pajsberg
[var: Manganophyllite] Igelström (1872) Översigt KVA, pp. 63-64. ; Hamberg, A. (1890): Mineralogische Studien. 7. Über die Manganophylle von der Grube Harstigen bei Pajsberg in Vermland. Geologiska Föreningen i Stockholm Förhandlingar 133, 567-579
  • Colorado
    • El Paso Co.
[Siderophyllite] Minerals of Colorado (1997) Eckel, E. B.
  • Connecticut
    • Tolland Co.
      • Willington
        • West Willington
Ague, J. J. (1995): Deep Crustal Growth of Quartz, Kyanite and Garnet into Large-Aperature, fluid-filled fractures, northeastern Connecticut, USA. Journal of Metamorphic Geology: 13: 299-314.
  • Massachusetts
    • Essex Co.
[Annite] Dana (1868), A System of Mineralogy, 5th edition; Dyar, M. Darby and Burns, Roger G. (1986): Miissbauer spectral study of ferruginous one-layer trioctahedral micas (American Mineralogist, Volume 71, pages 955-965).
  • New Jersey
    • Sussex Co.
      • Franklin Mining District
        • Franklin
          • Franklin Marble
[Fluorophlogopite] Dunn (1995)
        • Ogdensburg
          • Sterling Hill
[Phlogopite] Harold Moritz collection
[Fluorophlogopite] Tracy, Robert J. (1991) Ba-rich Micas from the Franklin Marble, Lime Crest and Sterling Hill, New Jersey, American Mineralogist, v76, p. 1683-1693.
      • Sparta Township
        • Franklin Marble
[Phlogopite] Jaszczak, John A. (1997), Unusual graphite crystals from the Lime Crest quarry, Sparta, New Jersey: Rocks & Minerals: 72(5): 330-334
  • New York
    • St. Lawrence Co.
      • West Pierrepont
[Phlogopite] George Robinson & Steven Chamberlain (2007) Gazetteer of major New York State mineral localities. Rocks & Minerals, 82, #6, 472-483.; George Robinson & Steven Chamberlain (2007) Gazetteer of major New York State mineral localities. Rocks & Minerals, 82, #6, 472-483.
  • Pennsylvania
    • Northampton Co.
      • Easton
        • Chestnut Hill (College Hill; Lafayette Hill; Mount Lafayette; Paxinosa Ridge)
          • C.K. Williams Quarry complex (Williams and Company Rock Quarry)
[Eastonite] The Mineralogy of Pennsylvania; Samual G. Gordon 1922; Pg 119 The Talc Deposits of Phillipburg, N.J. and Easton; Peck, F. B., Trenton 1905 8vo., 26pp Livi, K.J.T. and Veblen, D.R. (1987) “Eastonite” from Easton, Pennsylvania: A mixture of phlogopite and a new form of serpentine. American Mineralogist, 72, 113-125.
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