Bannisterite
A valid IMA mineral species
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About Bannisterite
Formula:
CaMn2+10(Si14Al2)O38(OH)8 · nH2O
Formerly given as (Ca,K,Na)(Mn2+,Fe2+)10(Si,Al)16O38(OH)8 · nH2O, with n ~ 5.5. Revised in 2026.
Colour:
Dark brown
Lustre:
Sub-Vitreous, Resinous, Greasy
Hardness:
4
Specific Gravity:
2.83 - 2.84
Crystal System:
Monoclinic
Name:
Named by Marie Louise Lindberg Smith and Clifford Frondel in 1968 in honor of Dr. Frederick Allan Bannister (14th May 1901, St Marys, Peckham, Borough of Camberwell, London, England - 4th October 1971, Surrey Mid-Eastern Registration District), mineralogist and x-ray crystallographer, formerly Keeper of Minerals, British Museum (Natural History), London, England, UK 1952-1953.
(Originally identified as ganophyllite in 1936 by William Frederic).
(Originally identified as ganophyllite in 1936 by William Frederic).
Dark brown flat platy aggregates.
A Ba analogue is known: UM1989-30-SiO:AlBaCaFeHKMgMn.
Chemically similar to tamaite (Ca-dominant member of the ganophyllite group).
Structurally related to the Stilpnomelane Group.
A Ba analogue is known: UM1989-30-SiO:AlBaCaFeHKMgMn.
Chemically similar to tamaite (Ca-dominant member of the ganophyllite group).
Structurally related to the Stilpnomelane Group.
Unique Identifiers
Mindat ID:
509
Long-form identifier:
mindat:1:1:509:2
IMA Classification of Bannisterite
Classification of Bannisterite
9.EG.75
9 : SILICATES (Germanates)
E : Phyllosilicates
G : Double nets with 6-membered and larger rings
9 : SILICATES (Germanates)
E : Phyllosilicates
G : Double nets with 6-membered and larger rings
74.1.1.4
74 : PHYLLOSILICATES Modulated Layers
1 : Modulated Layers with joined islands
74 : PHYLLOSILICATES Modulated Layers
1 : Modulated Layers with joined islands
16.16.15
16 : Silicates Containing Aluminum and other Metals
16 : Aluminosilicates of Mn
16 : Silicates Containing Aluminum and other Metals
16 : Aluminosilicates of Mn
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Ban | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
| Ban | Warr (2020) | Warr, L.N. (2020) Recommended abbreviations for the names of clay minerals and associated phases. Clay Minerals, 55, 261–264 doi:10.1180/clm.2020.30 |
Physical Properties of Bannisterite
Sub-Vitreous, Resinous, Greasy
Transparency:
Translucent
Colour:
Dark brown
Streak:
Creamy white
Hardness:
4 on Mohs scale
Cleavage:
Perfect
{001}
{001}
Fracture:
Micaceous
Comment:
Cleavages are smooth without ruling, A-structure, or imperfections typical of True Micas.
Density:
2.83 - 2.84 g/cm3 (Measured) 2.84 g/cm3 (Calculated)
Optical Data of Bannisterite
Type:
Biaxial
RI values:
nα = 1.544 - 1.574 nβ = 1.586 - 1.611 nγ = 1.589 - 1.612
2V:
Calculated: 18° to 28°
Birefringence:
0.045
Max. Birefringence:
δ = 0.038 - 0.045
Based on recorded range of RI values above.
Based on recorded range of RI values above.
Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
Moderate (positive)
Relative to Canada balsam mounting medium (n ≈ 1.537).
Relative to Canada balsam mounting medium (n ≈ 1.537).
This shows the grain boundary and Becke line effect under plane-polarised
light, based on the contrast between this mineral's average refractive
index and the mounting medium. It does not take into account mineral
colouration.
In focus
Interference Figure:
This shows the idealized biaxial acute bisectrix (Bxa) interference figure
- the conoscopic view for a grain cut perpendicular to the acute bisectrix, using
this mineral's 2V. The two small white dots mark the melatopes - the points
where the two optic axes emerge - and are shown only when they fall within the
field of view. The coloured bands are isochromatics, and the dark bands are
isogyres.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Dispersion:
r < v weak to moderate
Pleochroism:
Visible
Comments:
X colorless to pale yellow
Chemistry of Bannisterite
Mindat Formula:
CaMn2+10(Si14Al2)O38(OH)8 · nH2O
Formerly given as (Ca,K,Na)(Mn2+,Fe2+)10(Si,Al)16O38(OH)8 · nH2O, with n ~ 5.5. Revised in 2026.
Formerly given as (Ca,K,Na)(Mn2+,Fe2+)10(Si,Al)16O38(OH)8 · nH2O, with n ~ 5.5. Revised in 2026.
Element Weights:
Common Impurities:
Zn,Na
Crystallography of Bannisterite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
B2/b
Cell Parameters:
a = 22.26 Å, b = 16.36 Å, c = 24.66 Å
β = 94.28°
β = 94.28°
Ratio:
a:b:c = 1.361 : 1 : 1.507
Unit Cell V:
8,955.48 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Platy aggregates
Comment:
A2/a
Crystal Structure
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Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure
| ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
|---|---|---|---|---|---|---|---|
| 0012234 | Bannisterite | Heaney P J, Post J E, Evans H T (1992) The crystal structure of bannisterite Clays and Clay Minerals 40 129-144 | 1992 | Franklin Furnace, New Jersey, USA | 0 | 293 | |
| 0012233 | Bannisterite | Heaney P J, Post J E, Evans H T (1992) The crystal structure of bannisterite Clays and Clay Minerals 40 129-144 | 1992 | Broken Hill, Australia | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 12.33 Å | (100) |
| 11.5 Å | (2) |
| 8.78 Å | (2) |
| 8.43 Å | (2) |
| 7.95 Å | (2) |
| 7.11 Å | (4) |
| 6.82 Å | (4) |
| 6.61 Å | (2) |
| 6.38 Å | (2) |
| 6.16 Å | (2) |
| 5.93 Å | (2) |
| 5.56 Å | (6) |
| 5.20 Å | (6) |
| 4.91 Å | (2) |
| 4.71 Å | (2) |
| 4.593 Å | (10) |
| 4.28 Å | (6) |
| 4.21 Å | (2) |
| 4.09 Å | (16b) |
| 3.79 Å | (8) |
| 3.69 Å | (2) |
| 3.57 Å | (6) |
| 3.44 Å | (20) |
| 3.40 Å | (2) |
| 3.36 Å | (10) |
| 3.31 Å | (2) |
| 3.24 Å | (2) |
| 3.21 Å | (2) |
| 3.13 Å | (2) |
| 3.08 Å | (12) |
| 3.02 Å | (2) |
| 2.97 Å | (4) |
| 2.91 Å | (2) |
| 2.84 Å | (2) |
| 2.79 Å | (8) |
| 2.75 Å | (8) |
| 2.71 Å | (2) |
| 2.64 Å | (16) |
| 2.61 Å | (12) |
| 2.48 Å | (2) |
| 2.46 Å | (2) |
| 2.41 Å | (10) |
| 2.38 Å | (10) |
| 2.33 Å | (2) |
| 2.30 Å | (2) |
| 2.25 Å | (4) |
| 2.22 Å | (4) |
| 2.20 Å | (2) |
| 2.16 Å | (6) |
| 2.11 Å | (2) |
| 1.998 Å | (2b) |
| 1.930 Å | (4) |
| 1.916 Å | (2) |
| 1.885 Å | (2) |
| 1.860 Å | (2) |
| 1.831 Å | (2) |
| 1.796 Å | (2) |
| 1.754 Å | (2) |
| 1.720 Å | (2) |
| 1.708 Å | (4) |
| 1.668 Å | (2) |
| 1.657 Å | (2) |
| 1.633 Å | (4) |
| 1.614 Å | (8) |
| 1.599 Å | (8) |
| 1.573 Å | (2) |
| 1.561 Å | (4) |
| 1.546 Å | (2) |
| 1.537 Å | (2) |
| 1.516 Å | (2) |
| 1.505 Å | (2) |
| 1.451 Å | (2) |
| 1.442 Å | (2) |
| 1.430 Å | (2) |
| 1.407 Å | (2) |
| 1.386 Å | (2) |
| 1.367 Å | (2) |
| 1.349 Å | (2) |
| 1.343 Å | (2) |
| 1.332 Å | (2) |
| 1.320 Å | (2) |
| 1.311 Å | (2) |
| 1.300 Å | (2) |
| 1.287 Å | (2) |
| 1.278 Å | (2) |
| 1.269 Å | (2) |
Comments:
ICDD 21-57; Structurally similar to ganophyllite and the stilpnomelane group
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| High-? alteration and/or metamorphism | |
| 32 : Ba/Mn/Pb/Zn deposits, including metamorphic deposits |
Geological Setting:
Sulfide-bearing zinc deposits
Type Occurrence of Bannisterite
Co-Type Localities:
Place of Conservation of Type Material:
National Museum of Natural History, Washington, D.C., USA, numbers 145728-145730.
Natural History Museum, London, United Kingdom, number BM 1967,321.
Harvard University, Cambridge, Massachusetts, USA, numbers 91862, 91863, 108571, 128253.
Natural History Museum, London, United Kingdom, number BM 1967,321.
Harvard University, Cambridge, Massachusetts, USA, numbers 91862, 91863, 108571, 128253.
Geological Setting of Type Material:
Silicate-carbonate hosted zinc deposit.
Associated Minerals at Type Locality:
Synonyms of Bannisterite
Other Language Names for Bannisterite
Relationship of Bannisterite to other Species
Structurally related to group(s):
| Stilpnomelane Group | See also the related ganophyllite group. |
Common Associates
Associations Based on Photo Data:
| 27 photos of Bannisterite associated with Rhodonite | CaMn3Mn[Si5O15] |
| 7 photos of Bannisterite associated with Calcite | CaCO3 |
| 4 photos of Bannisterite associated with Rhodochrosite | MnCO3 |
| 2 photos of Bannisterite associated with Richterite | Na(CaNa)Mg5(Si8O22)(OH)2 |
| 1 photo of Bannisterite associated with Pyroxmangite | Mn2+SiO3 |
| 1 photo of Bannisterite associated with Galena | PbS |
Related Minerals - Strunz-mindat Grouping
| 9.EG.05 | Cymrite | BaAl2Si2(O,OH)8 · H2O |
| 9.EG.10 | Naujakasite | (Na,K)6(Fe2+,Mn2+,Ca)(Al,Fe)4Si8O26 |
| 9.EG.10 | Manganonaujakasite | Na6(Mn2+,Fe2+)Al4Si8O26 |
| 9.EG.15 | Dmisteinbergite | Ca(Al2Si2O8) |
| 9.EG.20 | Kampfite | Ba12(Si11Al5)O31(CO3)8Cl5 |
| 9.EG.25 | Vertumnite | Ca4Al4Si4O6(OH)24 · 3H2O |
| 9.EG.25 | Strätlingite | Ca2Al2SiO7 · 8H2O |
| 9.EG.30 | Eggletonite | (Na,K,Ca)xMn6(Si,Al)10O24(OH)4 · nH2O (x = 1-2; n = 7-11) |
| 9.EG.30 | Ganophyllite | (K,Na)xMn2+6(Si,Al)10O24(OH)4 · nH2O (x = 1-2; n = 7-11) |
| 9.EG.30 | Tamaite | (Ca,K,Na)xMn6(Si,Al)10O24(OH)4 · nH2O (x = 1-2; n = 7-11) |
| 9.EG.35 | Zussmanite | K(Fe,Mg,Mn)13(Si,Al)18O42(OH)14 |
| 9.EG.35 | Coombsite | KMn2+13(Si,Al)18O42(OH)14 |
| 9.EG.40 | 'Chalcodite' | K(Fe3+,Mg,Fe2+)8(Si,Al)12(O,OH)27 |
| 9.EG.40 | Parsettensite | (K,Na,Ca)7.5(Mn,Mg)49Si72O168(OH)50 · nH2O |
| 9.EG.40 | Lennilenapeite | K4Mn2+48[Si64Al8]O164(OH)52 · nH2O |
| 9.EG.40 | Stilpnomelane | K4Fe2+48[Si64Al8]O164(OH)52 · nH2O |
| 9.EG.45 | Latiumite | (Ca,K)4(Si,Al)5O11(SO4,CO3) |
| 9.EG.45 | Levantite | KCa3Al2(SiO4)(Si2O7)(PO4) |
| 9.EG.45 | Tuscanite | KCa6(Si,Al)10O22(SO4,CO3)2(OH) · H2O |
| 9.EG.50 | Jagoite | Pb18Fe3+4[Si4(Si,Fe3+)6][Pb4Si16(Si,Fe)4]O82Cl6 |
| 9.EG.50 | Friisite | Pb8Al3Si8O27Cl3 |
| 9.EG.55 | Wickenburgite | CaPb3Al2Si10O24(OH)6 |
| 9.EG.60 | Hyttsjöite | Pb18Ba2Ca5Mn2+2Fe3+2Si30O90Cl · 6H2O |
| 9.EG.65 | Armbrusterite | K5Na7Mn15[(Si9O22)4](OH)10 · 4H2O |
| 9.EG.70 | Roymillerite | Pb24Mg9(Si10O28)(CO3)10(BO3)(SiO4)(OH)13O5 |
| 9.EG.70 | Britvinite | [Pb7(OH)3F(BO3)2(CO3)][Mg4.5(OH)3(Si5O14)] |
| 9.EG.75 | Kayupovaite | Na2Mn10[(Si14Al2)O38(OH)8] · 7H2O |
| 9.EG.75 | 'UM1989-30-SiO:AlBaCaFeHKMgMn' | (Ba,Ca)(Mn,Fe,Mg)22(Si,Al)32O76(OH)16 · 12H2O |
Fluorescence of Bannisterite
Not fluorescent in UV
Other Information
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Internet Links for Bannisterite
mindat.org URL:
https://www.mindat.org/min-509.html
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References for Bannisterite
Reference List:
Pavlides, Louis; Milton, Charles (1962) Geology and manganese deposits of the Maple and Hovey Mountains area, Aroostook County, Maine, with a section on Lithology and mineralogy of the deposits. Professional Paper 362. US Geological Survey p.1-116. doi:10.3133/pp362
Smith, Marie Lindberg, Frondel, Clifford (1968) The related layered minerals ganophyllite, bannisterite, and stilpnomelane. Mineralogical Magazine and Journal of the Mineralogical Society, 36 (283) 893-913 doi:10.1180/minmag.1968.283.036.01
Dunn, Pete J., Leavens, Peter B., Norberg, Julie A., Ramik, Robert A. (1981) Bannisterite: new chemical data and empirical formulae. American Mineralogist, 66 (9-10) 1063-1067
Heaney, Peter J. (1992) The Crystal Structure of Bannisterite. Clays and Clay Minerals, 40 (2) 129-144 doi:10.1346/ccmn.1992.0400201
Jambor, L., Grew, Edward S. (1993) New Mineral Names. American Mineralogist, 78 (1-2) 233-238 pp.236-236
Ferrow, Embaie A., Hovmoller, Sven (1993) Crystallographic image processing (CIP) and high-resolution transmission electron microscopy (HRTEM) studies of bannisterite: a 2:1 type modulated layer silicate. European Journal of Mineralogy, 5 (1) 181-188 doi:10.1127/ejm/5/1/0181
Localities for Bannisterite
Showing 30 localities.
symbol to view information about a locality.
The Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for references and 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).
All localities listed without proper references should be considered as questionable.
Australia | |
| Birch (1999) |
| Birch (1999) | |
| Keith Compton collection |
Canada | |
| Canadian Museum of Nature collection |
Italy | |
| Castellaro et al. (2023) |
| Castellaro-Kampf |
| Analyses of Anthony Kampf of Natural ... |
Japan | |
| - (n.d.) |
| Masutomi Museum specimen (Kyoto) +1 other reference |
| Yamada (2004) |
| Matsubara (1981) |
| Yamada (2004) | |
| Sameshima +1 other reference |
Norway | |
| - (1985) +3 other references |
Romania | |
| Hîrtopanu et al. (2003) +1 other reference | |
| minerals-of-the-carpathians.eu (2008) |
| Hîrtopanu (1997) +1 other reference |
Russia | |
| Brusnitsyn et al. (2009) |
| Semkova +3 other references |
| Kassandrov et al. (2009) |
| Kassandrov et al. (2009) | |
| Brusnitsyn A.I. (2000) |
Slovakia | |
| republika +2 other references |
| Koděra et al. (1986) | |
| Pauliš et al. (2002) |
Sweden | |
| |
| Gatedal (n.d.) | |
UK (TL) | |
| Smith et al. (1968) +2 other references |
USA (TL) | |
| Smith et al. (1968) +1 other reference |
|
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Zinc Corporation Mine, Southern operations Mine, Broken Hill, Broken Hill district, Yancowinna Co., New South Wales, Australia