Pennantite Mineral Data

General Pennantite Information

Chemical Formula:

Mn5Al(Si3Al)O10(OH)8

Composition:

Molecular Weight = 708.96 gm

Manganese 38.75 % Mn 50.03 % MnO

Aluminum 7.61 % Al 14.38 % Al₂O₃

Silicon 11.88 % Si 25.42 % SiO₂

Hydrogen 1.14 % H 10.16 % H₂O

Oxygen 40.62 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Mn²⁺₅Al₂Si₃O₁₀(OH)₈

Environment:

Metamorhpic or hydrothermally altered manganese- and zinc-bearing assemblages.

IMA Status:

Valid Species (Pre-IMA) 1946

Locality:

Ty Canol incline, Benault mine, Rhiw, Carnarvonshire, Lleyn Peninsula, Gwynedd, Wales. Link to MinDat.org Location Data.

Name Origin:

Named for Thomas Pennant (1726-1798), Welsh naturalist.

Name Pronunciation:

Pennantite + Pronunciation

Synonym:

Grovesite

Pennantite Image

Images:

Pennantite

Comments: Dark brown micaceous pennantite.
Location: Gambatesa Mine, Val Graveglia, Genova, Liguria, Italy. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Pennantite Crystallography

Axial Ratios:

a:b:c =0.5771:1:1.5238

Cell Dimensions:

a = 5.454, b = 9.45, c = 14.4, Z = 2; beta = 97.2° V = 736.33 Den(Calc)= 3.20

Crystal System:

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

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

By Intensity(I/I_o): 7.1(1), 2.43(0.8), 3.57(0.8),

Physical Properties of Pennantite

Cleavage:

{001} Perfect

Color:

Orange red, Reddish brown.

Density:

3.06

Diaphaneity:

Translucent

Habit:

Microscopic Crystals - Crystals visible only with microscopes.

Habit:

Rosette - Bundled tabular aggregates resembling rose flower petals.

Hardness:

2-3 - Gypsum-Calcite

Luster:

Pearly

Streak:

brownish yellow

Optical Properties of Pennantite

Gladstone-Dale:

CI meas= 0.006 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.05 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.205,KPDmeas= 0.2144,KC= 0.2158
Ncalc = 1.66 - 1.69

Optical Data:

Biaxial (-), a=1.646, b=1.661, g=1.661, bire=0.0150, 2V(Calc)=0, 2V(Meas)=0.

Calculated Properties of Pennantite

Electron Density:

Bulk Density (Electron Density)=2.98 gm/cc
note: Specific Gravity of Pennantite =3.06 gm/cc.

Fermion Index:

Fermion Index = 0.0057467392
Boson Index = 0.9942532608

Photoelectric:

PE_Pennantite= 10.55 barns/electron
U=PE_Pennantite x rElectron Density= 31.42 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Pennantite is Not Radioactive

Pennantite Classification

Dana Class:

71.04.01.08 (71)Phyllosilicate Sheets of Six-Membered Rings

(71.04)interlayered 1:1, 2:1, and octahedra

(71.04.01)Chlorite group (Tri-Dioctahedral)

71.04.01.01 Donbassite Al2[Al2.33][Si3AlO10](OH)8 C 2/m 2/m

71.04.01.02 Cookeite LiAl4(Si3Al)O10(OH)8 P 2₁/a 2/m

71.04.01.03 Sudoite Mg2(Al,Fe)3Si3AlO10(OH)8 C 2/m 2/m

71.04.01.04 Clinochlore (Mg,Fe)5Al(Si3Al)O10(OH)8 C 2/m 2/m

71.04.01.05 Nimite (Ni,Mg,Fe)5Al(Si3Al)O10(OH)8 C 2/m 2/m

71.04.01.06 Baileychlore (Zn,Al,[])3[Fe2Al][Si3AlO10](OH)8 C1,C1 Tri

71.04.01.07 Chamosite (Fe,Mg,Fe)5Al(Si3Al)O10(OH,O)8 C 2/m 2/m

71.04.01.08 Pennantite Mn5Al(Si3Al)O10(OH)8 C 2/m 2/m

71.04.01.09 Orthochamosite! (Fe,Mg,Fe)5Al(Si3Al)O10(OH,O)8 C3m-pseudoHEX Ortho

71.04.01.10 Borocookeite! Li(13x)Al(4-x)(BSi3)O10(OH,F)8[x=0-0.33] pseudo C 2/m 2/m

Strunz Class:

09.EC.55 09 - SILICATES (Germanates)

09.E - Phyllosilicates

09.EC -Phyllosilicates with mica sheets, composed of tetrahedral and octahedral nets

09.EC.55 Donbassite Al2[Al2.33][Si3AlO10](OH)8 C 2/m 2/m

09.EC.55 Baileychlore (Zn,Al,[])3[Fe2Al][Si3AlO10](OH)8 C1,C1 Tri

09.EC.55 Clinochlore (Mg,Fe)5Al(Si3Al)O10(OH)8 C 2/m 2/m

09.EC.55 Cookeite LiAl4(Si3Al)O10(OH)8 P 2₁/a 2/m

09.EC.55 Chamosite (Fe,Mg,Fe)5Al(Si3Al)O10(OH,O)8 C 2/m 2/m

09.EC.55 Franklinfurnaceite Ca2(Fe,Al)MnMn3Zn2Si2O10(OH)8 C 2 2

09.EC.55 Nimite (Ni,Mg,Fe)5Al(Si3Al)O10(OH)8 C 2/m 2/m

09.EC.55 Gonyerite Mn3[Mn3Fe][(Si,Fe)4O10](OH,O)8 pseudo-HEX Ortho

09.EC.55 Odinite (Fe,Mg,Al,Fe,Ti,Mn)2.5(Si,Al)2O5(OH)4 Cm m

09.EC.55 Orthochamosite (Fe,Mg,Fe)5Al(Si3Al)O10(OH,O)8 C3m-pseudoHEX Ortho

09.EC.55 Pennantite Mn5Al(Si3Al)O10(OH)8 C 2/m 2/m

09.EC.55 Sudoite Mg2(Al,Fe)3Si3AlO10(OH)8 C 2/m 2/m

09.EC.55 Glagolevite! NaMg6[Si3AlO10](OH,O)8•H2O C1 1

09.EC.55 Borocookeite! Li(13x)Al(4-x)(BSi3)O10(OH,F)8[x=0-0.33] pseudo C 2/m 2/m

Other Pennantite Information

References:

NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

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

Search for Pennantite using:

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

Visit our Advertisers for Pennantite :

A Bijoux Google Search for Pennantite
Adam's Minerals Google Search for Pennantite
Cape Minerals Google Search for Pennantite
Dakota Matrix Minerals Google Search for Pennantite
Excalibur Mineral Corp. Google Search for Pennantite
Exceptional Minerals Google Search for Pennantite
John Betts Fine Minerals Search for Pennantite
McDougall Minerals Google Search for Pennantite
Mineral News Website Link
Rock and Mineral Shows Google Search for Pennantite
Weinrich Minerals, Inc. Google Search for Pennantite

Ask about Pennantite 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 Pennantite Specimen Label here :

Pennantite

Mn5Al(Si3Al)O10(OH)8
Dana No: 71.04.01.08 Strunz No: 09.EC.55
Locality:

Notes: