Bannisterite Mineral Data

[Content and History] [Recent Issues] [Back Issues] [Subscriptions] [Contacts]
See Also: [Diamond Crystals] [Excalibur Minerals] [Hudson Institute] [Minerals on CDROM]
Mineral News was founded some twenty years ago and has developed a following of
avid mineral collectors seeking timely information about new finds and other items
of interest to the collector community. Articles are solicited from collector and scientific authors.

General Bannisterite Information

Chemical Formula:

KCa(Mn,Fe++,Zn,Mg)21(Si,Al)32O76(OH)16•4-12(H2O)

Composition:

Molecular Weight = 3,734.70 gm

Potassium 0.84 % K 1.01 % K₂O

Sodium 0.12 % Na 0.17 % Na₂O

Calcium 0.97 % Ca 1.35 % CaO

Magnesium 1.89 % Mg 3.13 % MgO

Manganese 17.95 % Mn 23.17 % MnO

Aluminum 2.17 % Al 4.10 % Al₂O₃

Zinc 3.68 % Zn 4.58 % ZnO

Iron 5.23 % Fe 5.58 % FeO / 1.28 % Fe₂O₃

Silicon 21.43 % Si 45.85 % SiO₂

Hydrogen 1.09 % H 9.74 % H₂O

Oxygen 44.64 % O

______ ______

100.00 % 99.96 % = TOTAL OXIDE

Empirical Formula:

K_0.8Na_0.2Ca_0.9Mn²⁺_12.2Fe²⁺_2.9Mg_2.9Zn_2.1Fe³⁺_0.6Si_28.5Al₃O₇₆(OH)₁₆·12.2(H₂O)

Environment:

Metamorphosed Mn-Zn orebodies.

IMA Status:

Valid Species (Pre-IMA) 1936

Locality:

In the Banallt mine, Rhiw, Lleyn Peninsula, Wales. Link to MinDat.org Location Data.

Name Origin:

Named for Dr. Frederick Allen Bannister (1901-?), formerly Keeper of Minerals, British Museum (Natural History), London, England.

Name Pronunciation:

Bannisterite + Pronunciation

Synonym:

ICSD 80078

PDF 46-1281

Bannisterite Image

Images:

Bannisterite

Comments: Deep red micaceous bannisterite.
Location: Zinc Mine, Broken Hill, New South Wales, Australia. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Bannisterite Crystallography

Axial Ratios:

a:b:c =1.3602:1:1.507

Cell Dimensions:

a = 22.265, b = 16.368, c = 24.668, Z = 4; beta = 94.285° V = 8,964.72 Den(Calc)= 2.77

Crystal System:

Monoclinic - PrismaticH-M Symbol (2/m) Space Group: A2/a

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 12.33(1), 3.44(0.2), 4.1(0.16),

Crystal Structure:

Mouse
drag1 - LMB Manipulate Structure
drag2 - RMB Resize/Rotate
Keyboard
S - Stereo Pair on/off
H - Help Screen
I - Data Info
A - Atoms On/Off
P - Polyhedra On/Off
B - Bonds On/Off
Help on Above

Heaney P J , Post J E , Evans H T , Clays and Clay Minerals , 40 (1992) p.129-144, The crystal structure of bannisterite, Locality: Broken Hill, Australia

View Additional jPOWD Structure files for Bannisterite
[1]

Physical Properties of Bannisterite

Cleavage:

{001} Perfect, {???} Distinct

Color:

Dark brown, Black.

Density:

2.83 - 2.84, Average = 2.83

Diaphaneity:

Translucent

Habit:

Aggregates - Made of numerous individual crystals or clusters.

Habit:

Bladed - Aggregates of thin lath-like crystals (e.g. kyanite).

Habit:

Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).

Hardness:

4 - Fluorite

Luster:

Resinous

Optical Properties of Bannisterite

Gladstone-Dale:

CI meas= 0.042 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= 0.02 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2116,KPDmeas= 0.2067,KC= 0.2158
Ncalc = 1.6 - 1.61

Optical Data:

Biaxial (?), a=1.544-1.574, b=1.586-1.611, g=1.589-1.612, bire=0.0380-0.0450, 2V(Calc)=18-28, 2V(Meas)=small. Dispersion r < v moderate.

Calculated Properties of Bannisterite

Electron Density:

Bulk Density (Electron Density)=2.73 gm/cc
note: Specific Gravity of Bannisterite =2.77 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Bannisterite= 8.99 barns/electron
U=PE_Bannisterite x r_electron= 24.57 barns/cc.

Radioactivity:

GRapi = 11.93 (Gamma Ray American Petroleum Institute Units)
Concentration of Bannisterite per GRapi unit = 8.39 (%)

Estimated Radioactivity from Bannisterite - barely detectable

Bannisterite Classification

Dana Class:

74.01.01.04 (74)Phyllosilicate Modulated Layers

(74.01)with joined islands

(74.01.01)Stilpnomelane group

74.01.01.01 Stilpnomelane K(Fe,Mg,Fe)8(Si,Al)12(O,OH)27•n(H2O) P1 1

74.01.01.02 Lennilenapeite K6-7(Mg,Mn,Fe,Fe,Zn)48(Si,Al)72(O,OH)216•16(H2O) Unk (pseudo-HEX) Tri

74.01.01.03 Franklinphilite (K,Na)4(Mn,Mg,Zn)48(Si,Al)72(O,OH)216•6(H2O) pseudo-HEX P1 or P1 Tri

74.01.01.04 Bannisterite KCa(Mn,Fe,Zn,Mg)21(Si,Al)32O76(OH)16•4-12(H2O) A2/a 2/m

74.01.01.05 Middendorfite! K3Na2Mn5Si12(O,OH)36•2H2O P 2₁/m or P 2₁ Mono

Strunz Class:

09.EG.75 09 - SILICATES (Germanates)

09.E - Phyllosilicates

09.EG -Double nets with 6-membered and larger rings

09.EG.75 Bannisterite KCa(Mn,Fe,Zn,Mg)21(Si,Al)32O76(OH)16•4-12(H2O) A2/a 2/m

Other Bannisterite Information

References:

NAME( AntBidBlaNic2) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic2)

See Also:

Links to other databases for Bannisterite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - Franklin Minerals(Dunn)
6 - GeoScienceWorld
7 - Google Images
8 - Google Scholar
9 - Handbook of Mineralogy (MinSocAm)
10 - Handbook of Mineralogy (UofA)
11 - MinDAT
12 - Mineralienatlas (Deutsch)
13 - Online Mineral Museum
14 - QUT Mineral Atlas
15 - Ruff.Info
16 - WWW-MINCRYST

Search for Bannisterite using:

[AOL] [Bing] [Dog Pile] [GeoScienceWorld] [HotBot] [Ixquick] [Lycos] [MAMMA] [Scirus] [Teoma] [WebCrawler] [Wikipedia] [YAHOO]

Visit our Advertisers for Bannisterite :

B and L Fine Minerals
Dakota Matrix Minerals
Dan & Diana Weinrich Mineral Auctions
Excalibur Mineral Corp.
Exceptional Minerals
John Betts Fine Minerals
Mineral News
Mineral of the Month Club
NY/NJ Gem & Mineral Show
TIMA Mineral Analyzer
Weinrich Minerals, Inc.
Wright's Rock Shop

Ask about Bannisterite here :
Ask-A-Mineralogist from the Mineralogical Society of America
Mindat.org's Discussion Groups
Original Rockhounds Discussion Group
Rockhounds Discussion Group on Yahoo Groups
Mineral Discussion Forum from Fabre Minerals - also available in Español

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

Bannisterite

KCa(Mn,Fe++,Zn,Mg)21(Si,Al)32O76(OH)16•4-12(H2O)
Dana No: 74.01.01.04 Strunz No: 09.EG.75
Locality:

Notes: