| |
 |
Psilomelane Mineral Data
|
|
|
General Psilomelane Information
|
 Chemical Formula: |
(Ba,H2O)2Mn5O10 |
| 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 |
| Empirical Formula: |
Ba•(H2O)Mn3+5O10 |
| Environment: |
General term for hard, black Mn oxides. Romanechite is one of the most common species. |
| IMA Status: |
Discredited IMA 1982 |
| Locality: |
Common world wide. Link to MinDat.org Location Data. |
| Name Origin: |
Named in 1758 from the Greek psilos - "smooth" and melas - "black." |
| Name Pronunciation: |
Psilomelane + Pronunciation  |
| |
Psilomelane Image |
|
Images:
|
|
Psilomelane Crystallography
|
| Axial Ratios: |
a:b:c =3.3194:1:4.809 |
| Cell Dimensions: |
a = 9.56, b = 2.88, c = 13.85, Z = 2; beta = 92.5° V = 380.97 Den(Calc)= 5.14 |
| Crystal System: |
Monoclinic - Prismatic H-M Symbol (2/m) Space Group: A2/m |
| |
Physical Properties of Psilomelane
|
| Cleavage: |
None |
| Color: |
Iron black, Dark steel gray. |
| Density: |
4.4 - 4.7, Average = 4.55 |
| Diaphaneity: |
Opaque |
| Fracture: |
Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern. |
| Habit: |
Botryoidal - "Grape-like" rounded forms (e.g.. malachite). |
| Habit: |
Mammillary - Larger "breast-like" rounded forms resembling botryoidal (e.g. malachite). |
| Habit: |
Reniform - "Kidney like" in shape (e.g.. hematite). |
| Hardness: |
5-6 - Between Apatite and Orthoclase |
| Luminescence: |
Non-fluorescent. |
| Luster: |
Sub Metallic |
| Magnetism: |
Nonmagnetic |
| Streak: |
brownish black |
| |
Optical Properties of Psilomelane
|
| 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
|
| Electron Density: |
Bulk Density (Electron Density)=4.72 gm/cc
note: Specific Gravity of Psilomelane =5.14 gm/cc.
|
| Fermion Index: |
Fermion Index = 0.04
Boson Index = 0.96 |
| Photoelectric: |
PEPsilomelane = 114.11 barns/electron
U=PEPsilomelane x rElectron Density= 538.80 barns/cc.
|
| Radioactivity: |
GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Psilomelane is Not Radioactive |
| |
Psilomelane Classification
|
| 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 |
| 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
|
| References: |
NAME( Duda&Rejl90) PHYS. PROP.(Mason68) |
| 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
Search for Psilomelane using:
[AOL]
[Bing]
[Dog Pile]
[GeoScienceWorld]
[HotBot]
[Ixquick]
[Lycos]
[MAMMA]
[Scirus]
[Teoma]
[WebCrawler]
[Wikipedia]
[YAHOO]
Visit our Advertisers for Psilomelane :
Ask about Psilomelane 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
Espaņol
Print or Cut-and-Paste your Psilomelane Specimen Label here :
|
Psilomelane
(Ba,H2O)2Mn5O10
Dana No: 07.09.02.00 Strunz No: 04.XX.00
Locality:
Notes:
|
|
| |
| |
|
| |
Dakota Matrix
Excalibur Minerals
Exceptional Minerals
Hudson Insitute
John Betts Fine Minerals
Mc Dougall Minerals
Mineral News
Rock and Mineral Shows
Weinrich Minerals, Inc.
