| |
 |
Stilpnomelane Mineral Data
|
|
|
General Stilpnomelane Information
|
 Chemical Formula: |
K(Fe++,Mg,Fe+++)8(Si,Al)12(O,OH)27•n(H2O) |
| Composition: |
Molecular Weight = 1,247.57 gm |
| |
Potassium 3.13 % K |
| |
Magnesium 2.73 % Mg |
| |
Aluminum 4.33 % Al |
| |
Iron 29.54 % Fe |
| |
Silicon 22.51 % Si |
| |
Hydrogen 0.57 % H |
| |
Oxygen 37.19 % O |
| |
______ |
| |
100.00 % |
| Empirical Formula: |
KFe2+4.3Mg1.4Fe3+2.3Si10Al2O24(OH)3�2(H2O) |
| Environment: |
Commonly associated with iron ores. |
| IMA Status: |
Valid Species (Pre-IMA) 1827 |
| Locality: |
Moravia of Czechoslovakia at Sternberg in a bed of limonite. Link to MinDat.org Location Data. |
| Name Origin: |
From the Greek for "shining" and "black", in allusion to its luster and color. |
| Name Pronunciation: |
Stilpnomelane + Pronunciation  |
| Synonym: |
Ferristilpnomelane - high Fe+++ |
| |
Ferrostilpnomelane - Low Fe+++ |
| |
Stilpnomelane Image |
|
Images:
|
|
Stilpnomelane Crystallography
|
| Axial Ratios: |
a:b:c =1:1:0.8073 |
| Cell Dimensions: |
a = 21.8, b = 21.8, c = 17.6, Z = 6; alpha = 125.03°, beta = 95.98°, gamma = 120° V = 5,899.18 Den(Calc)= 2.11 |
| Crystal System: |
Triclinic - Pinacoidal H-M Symbol ( 1) Space Group: P1 |
| X Ray Diffraction: |
By Intensity(I/Io): 2.55(1), 4.16(1), 12.3(1), |
| |
Physical Properties of Stilpnomelane
|
| Cleavage: |
{001} Perfect |
| Color: |
Brown red, Green, Golden brown, Black. |
| Density: |
2.77 - 2.96, Average = 2.86 |
| Diaphaneity: |
Subtranslucent to opaque |
| Fracture: |
Brittle - Generally displayed by glasses and most non-metallic minerals. |
| Habit: |
Fibrous - Crystals made up of fibers. |
| Habit: |
Foliated - Two dimensional platy forms. |
| Habit: |
Platy - Sheet forms (e.g. micas). |
| Hardness: |
3 - Calcite |
| Luminescence: |
Non-fluorescent. |
| Luster: |
Vitreous - Dull |
| Streak: |
gray white |
| |
Optical Properties of Stilpnomelane
|
| Optical Data: |
Biaxial (-), a=1.543-1.634, b=1.576-1.745, g=1.576-1.745, bire=0.0330-0.1110, 2V(Calc)=0, 2V(Meas)=0-40. Dispersion none. |
| Pleochroism (x): |
pale yellow, golden yellow, pale brown, or colorless. |
| Pleochroism (y): |
deep brown, nearly black, chestnut brown, deep yellowish brown, or light greenish yellow. |
| Pleochroism (z): |
deep brown, nearly black, chestnut brown, deep yellowish brown, or light greenish yellow. |
| |
Calculated Properties of Stilpnomelane
|
| Electron Density: |
Bulk Density (Electron Density)=2.46 gm/cc
note: Specific Gravity of Stilpnomelane =2.51 gm/cc.
|
| Fermion Index: |
Fermion Index = 0.01
Boson Index = 0.99 |
| Photoelectric: |
PEStilpnomelane = 10.10 barns/electron
U=PEStilpnomelane x relectron= 24.89 barns/cc.
|
| Radioactivity: |
GRapi = 44.41 (Gamma Ray American Petroleum Institute Units)
Concentration of Stilpnomelane per GRapi unit = 2.25 (%)
Estimated Radioactivity from Stilpnomelane  - barely detectable
|
| |
Stilpnomelane Classification
|
| Dana Class: |
74.01.01.01 (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.40 09 - SILICATES (Germanates) |
| |
09.E - Phyllosilicates |
| |
09.EG -Double nets with 6-membered and larger rings |
| |
09.EG.40 Franklinphilite (K,Na)4(Mn,Mg,Zn)48(Si,Al)72(O,OH)216•6(H2O) pseudo-HEX P1 or P1 Tri |
| |
09.EG.40 Ekmanite? (Fe,Mg,Mn,Fe)3(Si,Al)4O10(OH)2•2(H2O) Unk Ortho |
| |
09.EG.40 Lennilenapeite K6-7(Mg,Mn,Fe,Fe,Zn)48(Si,Al)72(O,OH)216•16(H2O) Unk (pseudo-HEX) Tri |
| |
09.EG.40 Parsettensite (K,Na,Ca)(Mn,Al)7Si8O20(OH)8•2(H2O)(?) C 2/m 2/m |
| |
09.EG.40 Stilpnomelane K(Fe,Mg,Fe)8(Si,Al)12(O,OH)27•n(H2O) P1 1 |
| |
Other Stilpnomelane Information
|
| References: |
NAME( Ford32) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990) |
| See Also: |
Links to other databases for Stilpnomelane :
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 - Minerals in Thin Section-University of North Carolina
13 - Minerals in Thin Sections-Humboldt State
14 - Online Mineral Museum
15 - QUT Mineral Atlas
16 - Ruff.Info
Search for Stilpnomelane using:
[AOL]
[Bing]
[Dog Pile]
[GeoScienceWorld]
[HotBot]
[Ixquick]
[Lycos]
[MAMMA]
[Scirus]
[Teoma]
[WebCrawler]
[Wikipedia]
[YAHOO]
Visit our Advertisers for Stilpnomelane :
Ask about Stilpnomelane 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 Stilpnomelane Specimen Label here :
|
Stilpnomelane
K(Fe++,Mg,Fe+++)8(Si,Al)12(O,OH)27•n(H2O)
Dana No: 74.01.01.01 Strunz No: 09.EG.40
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.
