Biotite : CSIRO Spectroscopy Database

Biotite [ K(Mg,Fe)₃AlSi₃O₁₀(OH,F)₂ ]

Image of Biotite

Biotite specimen from Rist Mine, Hiddenite, Alexander County, North Carolina, USA

Rob Lavinsky, iRocks.com – CC-BY-SA-3.0

Material properties

Formula	K(Mg,Fe)₃AlSi₃O₁₀(OH,F)₂
Abbreviation	Bt
IMA Status	Approved group
Crystal symmetry	Monoclinic, Point group 2/m, Space group C2/m (#12)
Classification	Mica
Members	Biotite-1M, Fluorophlogopite, Tetraferriphlogopite, Fluorannite, Oxyphlogopite, Biotite-2M1, Annite, Tetraferriannite, Fluorophlogopite (var. synthetic), Eastonite, Phlogopite (var. Fe), Phlogopite, Siderophyllite, Fluorotetraferriphlogopite
Search other databases	webmineral.com, mindat.org, rruf.info, mineralienatlas.de, Handbook of Mineralogy, American Mineralogist Crystal Structure Database
Tags	Aluminosilicate, Hydroxide, Subgroup

Composition

Element	Wt%
H	0.41
K	9.02
Mg	14.02
Fe	6.44
Al	6.22
Si	19.44
O	43.36
F	1.1
Total:	100.01

References for Biotite

CSIRO spectra 2015 (Noril'sk-Kharelakh)

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2

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Torpy et al. 2020

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2

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Specimens of Biotite

Name	Owner	Materials	Image	Spectra	Techniques
Erwan1 Biotite	CSIRO	Albite (var. Ca), Biotite, Biotite-1M, Kaolinite, Quartz	Erwan1 Biotite Image of Biotite-1M, Albite (var. Ca), Kaolinite and Quartz in specimen 'Erwan1 Biotite' [CSIRO]. (C) 2025 CSIRO Mineral Resources. All rights reserved.	0	—
Erwan2 Biotite	CSIRO	Albite (var. Ca), Biotite, Biotite-1M, Clinochlore (var. Fe), Quartz	Erwan2 Biotite Image of Biotite-1M, Albite (var. Ca), Clinochlore (var. Fe) and Quartz in specimen 'Erwan2 Biotite' [CSIRO]. (C) 2025 CSIRO Mineral Resources. All rights reserved.	0	—
KH-2	CSIRO	Amphibole, Apatite, Augite, Biotite, Calcite, Chalcopyrite, Chlorapatite, Enstatite, Forsterite, Ilmenite, Magnetite, Pentlandite, Plagioclase, Pyrite, Pyroxene, Pyrrhotite	KH-2 Clustered EPMA phase map of the KH-2 specimen (owner: S. Barnes, CSIRO Mineral Resources), from the Kharelakh intrusion, Noril'sk, Russia (C) 2015 CSIRO Process Science and Engineering. All Rights reserved.	26	CL, EDS
M1593 Biotite	CSIRO	Biotite, Biotite-1M, Biotite-2M1, Quartz	M1593 Biotite Image of specimen 'M1593 Biotite' [CSIRO], from Torrington, Tenterfield Shire, New England Region, NSW, Australia. (C) 2025 CSIRO Mineral Resources. All rights reserved.	0	—
MES001 Biotite	CSIRO	Biotite, Biotite-1M, Kaolinite, Phlogopite-1M, Quartz	MES001 Biotite Image of Biotite, Kaolinite, Phlogopite and Quartz in specimen 'MES001 Biotite' [CSIRO]. (C) 2026 CSIRO Mineral Resources. All rights reserved.	0	—
Tista 2020 D4 Shaker	CSIRO	Albite, Allanite-(Ce), Amphibole, Andesine, Apatite, Augite, Biotite, Bytownite, Chlorite (var. Mg, Fe), Epidote, Garnet, Grossular, Ilmenite, Ilmenite (var. Mn), K feldspar, Kyanite, Monazite-(Ce), Muscovite, Oligoclase, Pyroxene, Quartz, Staurolite, Titanite, Titanohematite, Xenotime-(Y), Zircon, Zoisite	Tista 2020 D4 Shaker Clustered phase map of river sands (D4 shaker), from the Tista River, Bangladesh. From Torpy et al. 2020 (C) 2020 CSIRO Mineral Resources	46	CL, EDS
Tista 2020 D4 Zircon conc	CSIRO	Albite, Apatite, Biotite, Florencite-(Ce), Ilmenite, K feldspar, Kyanite, Monazite-(Ce), Muscovite, Plagioclase, Quartz, Rutile, Scheelite, Titanite, Zircon, Zoisite	Tista 2020 D4 Zircon conc Image of a specimen of Zircon from Tista River, Bangladesh (C) 2020 CSIRO Mineral Resources	27	CL, EDS