General Willemseite Information Chemical Formula: |
(Ni,Mg)3Si4O10(OH)2 |
Composition: |
Molecular Weight = 456.63 gm |
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Magnesium 3.99 % Mg 6.62 % MgO |
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Silicon 24.60 % Si 52.63 % SiO2 |
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Nickel 28.92 % Ni 36.80 % NiO |
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Hydrogen 0.44 % H 3.95 % H2O |
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Oxygen 42.05 % O |
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100.00 % 100.00 % = TOTAL OXIDE |
Empirical Formula: |
Ni2.25Mg0.75Si4O10(OH)2 |
Environment: |
Massive, fine-grained material. |
IMA Status: |
Approved IMA 1970 |
Locality: |
Scotia talc mine, Bon Accord, Barberton district, Transvaal, South Africa. Link to MinDat.org Location Data. |
Name Origin: |
Named for Johannes Willemse (1909-?), geologist University of Pretoria, South Africa. |
Name Pronunciation: |
Willemseite + Pronunciation |
Synonym: |
Pimelite - (Mg, H20) |
| | Willemseite Image
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Willemseite Crystallography Axial Ratios: |
a:b:c =0.581:1:2.076 |
Cell Dimensions: |
a = 5.316, b = 9.149, c = 18.994, Z = 4; beta = 99.96° V = 909.87 Den(Calc)= 3.33 |
Crystal System: |
Monoclinic - PrismaticH-M Symbol (2/m) Space Group: C 2/c |
X Ray Diffraction: |
By Intensity(I/Io): 9.4(1), 3.12(0.28), 2.503(0.23), |
| Physical Properties of Willemseite Cleavage: |
{001} Perfect |
Color: |
Light green. |
Density: |
3.31 |
Hardness: |
2 - Gypsum |
Streak: |
greenish white |
| Optical Properties of Willemseite Gladstone-Dale: |
CI meas= 0.044 (Good) - where the CI = (1-KPDmeas/KC) |
CI calc= 0.05 (Good) - where the CI = (1-KPDcalc/KC) KPDcalc= 0.1909,KPDmeas= 0.192,KC= 0.2009 Ncalc = 1.66 - 1.67 Optical Data: |
Biaxial (-), a=1.6, b=1.652, g=1.655, bire=0.0550, 2V(Calc)=26, 2V(Meas)=27. |
| Calculated Properties of Willemseite Electron Density: |
Bulk Density (Electron Density)=3.28 gm/cc |
note: Specific Gravity of Willemseite =3.31 gm/cc. Fermion Index: |
Fermion Index = 0.01 |
Boson Index = 0.99 Photoelectric: |
PEWillemseite = 12.39 barns/electron |
U=PEWillemseite x rElectron Density= 40.60 barns/cc. Radioactivity: |
GRapi = 0 (Gamma Ray American Petroleum Institute Units) |
Willemseite is Not Radioactive | Willemseite Classification Dana Class: |
71.02.01.04 (71)Phyllosilicate Sheets of Six-Membered Rings |
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(71.02)with 2:1 Layers |
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(71.02.01)Pyrophyllite-talc group |
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Strunz Class: |
09.EC.05 09 - SILICATES (Germanates) |
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09.E - Phyllosilicates |
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09.EC -Phyllosilicates with mica sheets, composed of tetrahedral and octahedral nets |
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| Other Willemseite 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 Willemseite : |
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 Willemseite using: Visit our Advertisers for Willemseite : A Bijoux Google Search for WillemseiteAdam's Minerals Google Search for Willemseite Cape Minerals Google Search for Willemseite Dakota Matrix Minerals Google Search for Willemseite Excalibur Mineral Corp. Google Search for Willemseite Exceptional Minerals Google Search for Willemseite John Betts Fine Minerals Search for Willemseite McDougall Minerals Google Search for Willemseite Mineral News Website Link Rock and Mineral Shows Google Search for Willemseite Weinrich Minerals, Inc. Google Search for Willemseite Ask about Willemseite here : Print or Cut-and-Paste your Willemseite Specimen Label here :
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