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Psilomelane Mineral Data

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General Psilomelane Information

Help on Chemical  Formula: Chemical Formula: (Ba,H2O)2Mn5O10
Help on Composition: Composition: Molecular Weight = 590.03 gm
   Barium     23.27 %  Ba   25.99 % BaO
   Manganese  46.56 %  Mn   66.89 % Mn2O3
   Hydrogen    0.34 %  H     3.05 % H2O
   Oxygen     29.83 %  O
             ______        ______ 
             100.00 %       95.93 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Ba•(H2O)Mn3+5O10
Help on Environment: Environment: General term for hard, black Mn oxides. Romanechite is one of the most common species.
Help on IMA Status: IMA Status: Discredited IMA 1982
Help on Locality: Locality: Common world wide. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named in 1758 from the Greek psilos - "smooth" and melas - "black."
Help on Name Pronunciation: Name Pronunciation: Psilomelane + Pronunciation Say PSILOMELANE
 

Psilomelane Image

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  Psilomelane

Comments: Banded massive psilomelane.
Location: Compton, Virginia, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Psilomelane Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =3.3194:1:4.809
Help on Cell Dimensions: Cell Dimensions: a = 9.56, b = 2.88, c = 13.85, Z = 2; beta = 92.5° V = 380.97 Den(Calc)= 5.14
Help on Crystal System: Crystal System: Monoclinic - Prismatic H-M Symbol (2/m) Space Group: A2/m
 

Physical Properties of Psilomelane

Help on Cleavage: Cleavage: None
Help on Color: Color: Iron black, Dark steel gray.
Help on Density: Density: 4.4 - 4.7, Average = 4.55
Help on Diaphaneity: Diaphaneity: Opaque
Help on Fracture: Fracture: Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern.
Help on Habit: Habit: Botryoidal - "Grape-like" rounded forms (e.g.. malachite).
Help on Habit: Habit: Mammillary - Larger "breast-like" rounded forms resembling botryoidal (e.g. malachite).
Help on Habit: Habit: Reniform - "Kidney like" in shape (e.g.. hematite).
Help on Hardness: Hardness: 5-6 - Between Apatite and Orthoclase
Help on Luminescence: Luminescence: Non-fluorescent.
Help on Luster: Luster: Sub Metallic
Help on Magnetism: Magnetism: Nonmagnetic
Help on Streak: Streak: brownish black
 

Optical Properties of Psilomelane

Help on Optical Data: Optical Data: NCalc= 2.26 - from Gladstone-Dale relationship (KC = 0.245) where Ncalc=Dcalc*KC+1
NCalc= 2.11 - from Gladstone-Dale relationship (KC = 0.245) where Ncalc=Dmeas*KC+1
 

Calculated Properties of Psilomelane

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=4.72 gm/cc
note: Specific Gravity of Psilomelane =5.14 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.04
Boson Index = 0.96
Help on Photoelectric: Photoelectric: PEPsilomelane = 114.11 barns/electron
U=PEPsilomelane x rElectron Density= 538.80 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Psilomelane is Not Radioactive
 

Psilomelane Classification

Help on  Dana Class: Dana Class: 07.09.02.00 (07)Multiple Oxides
  (07.09)Dana Type
  (07.09.02)Dana Group
 
07.09.02.00 Psilomelane? (Ba,H2O)2Mn5O10 A2/m 2/m
 
07.09.02.01 Romanechite (Ba,H2O)2(Mn,Mn)5O10 C 2/m 2/m
Help on  Strunz Class: Strunz Class: 04.XX.00 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate
  04.X - Unclassified Strunz OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, telluri
  04.XX -Oxide
 
04.XX.00 Ashanite? (Nb,Ta,U,Fe,Mn)4O8 Pcan 2/m 2/m 2/m
 
04.XX.00 Methane hydrate-I! 46(H2O)•2(S)•6(L) P m3n 4/m 3 2/m
 
04.XX.00 Clinobirnessite* Na4Mn14O27•9(H2O) Mono
 
04.XX.00 Chubutite* Pb7O6Cl2 Unk Ortho
 
04.XX.00 Kleberite* FeTi6O13•4(H2O)(?) P 63mcm ? 6mm
 
04.XX.00 Hongquiite* TiO F m3m 4/m 3 2/m
 
04.XX.00 Psilomelane? (Ba,H2O)2Mn5O10 A2/m 2/m
 
04.XX.00 Struverite? (Ti,Ta,Fe)O2 P 4/mnm 4/m 2/m 2/m
 
04.XX.00 Ungursaite* NaCa5(Ta,Nb)24O65(OH) P 63/m,P 63 Hex
 
04.XX.00 Uhligite? Ca3(Ti,Al,Zr)9O20 Unk Cubic
 
04.XX.00 Scheteligite? (Ca,Y,Sb,Mn)2(Ti,Ta,Nb,W)2O6(O,OH) Unk Ortho
 
04.XX.00 Allendeite! Sc4Zr3O12 R 3 3
 
04.XX.00 IMA2000-016! (Ti,Fe,Mg,Mn)1-xTi2O5 Pban 2/m 2/m 2/m
 
04.XX.00 Methane hydrate-II! 136(H2O)•16(S)•8(L) F d3m 4/m 3 2/m
 
04.XX.00 IMA2000-026! (Mn,Li)4(Ta,Sn)4(Ta,Nb)8O32 C 2/c 2/m
 
04.XX.00 Methane hydrate-H! 34(H2O)•3(S)•2(M)•1(L) P 6/mmm 6/m 2/m 2/m
 

Other Psilomelane Information

Help on References: References: NAME( Duda&Rejl90) PHYS. PROP.(Mason68)
Help on See Also: See Also: Links to other databases for Psilomelane :
1 - Am. Min. Crystal Structure Database
2 - Amethyst Galleries' Mineral Gallery
3 - Athena
4 - Franklin Minerals(Palache)
5 - GeoScienceWorld
6 - Glendale Community College
7 - Google Images
8 - Google Scholar
9 - MinDAT
10 - Mineralienatlas (Deutsch)
11 - Online Mineral Museum
12 - QUT Mineral Atlas
13 - Ruff.Info
14 - WWW-MINCRYST

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Psilomelane

(Ba,H2O)2Mn5O10
Dana No: 07.09.02.00 Strunz No: 04.XX.00
Locality:

 

Notes:

 

 
   
 


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