General Posnjakite Information Chemical Formula: |
Cu4(SO4)(OH)6•(H2O) |
Composition: |
Molecular Weight = 470.31 gm |
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Copper 54.05 % Cu 67.65 % CuO |
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Hydrogen 1.71 % H 15.32 % H2O |
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Sulfur 6.82 % S 17.02 % SO3 |
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Oxygen 37.42 % O |
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______ ______ |
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100.00 % 100.00 % = TOTAL OXIDE |
Empirical Formula: |
Cu4(SO4)(OH)6•(H2O) |
IMA Status: |
Approved IMA 1967 |
Locality: |
Link to MinDat.org Location Data. |
Name Origin: |
Named after the geochemist, E. W. Posnjak (1888-1949). |
Name Pronunciation: |
Posnjakite + Pronunciation |
Synonym: |
ICSD 100276 |
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PDF 43-670 |
| | Posnjakite Image
Images:
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Posnjakite Crystallography Axial Ratios: |
a:b:c =2.2454:1:1.6673 |
Cell Dimensions: |
a = 14.236, b = 6.34, c = 10.571, Z = 4; beta = 102.917° V = 929.96 Den(Calc)= 3.36 |
Crystal System: |
Monoclinic - PrismaticH-M Symbol (2/m) Space Group: C 2/c |
X Ray Diffraction: |
By Intensity(I/Io): 6.94(1), 3.47(0.3), 2.7(0.25), |
Crystal Structure:
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Mouse
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| Physical Properties of Posnjakite Cleavage: |
{???} Perfect |
Color: |
Blue, Dark blue. |
Density: |
3.4 |
Fracture: |
Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern. |
Habit: |
Crystalline - Fine - Occurs as well-formed fine sized crystals. |
Habit: |
Encrustations - Forms crust-like aggregates on matrix. |
Habit: |
Platy - Sheet forms (e.g. micas). |
Hardness: |
2.5-3 - Finger Nail-Calcite |
Luster: |
Vitreous (Glassy) |
Streak: |
greenish blue |
| Optical Properties of Posnjakite Gladstone-Dale: |
CI meas= 0 (Superior) - where the CI = (1-KPDmeas/KC) |
CI calc= -0.011 (Superior) - where the CI = (1-KPDcalc/KC) KPDcalc= 0.1995,KPDmeas= 0.1972,KC= 0.1972 Ncalc = 1.66 - 1.67 Optical Data: |
Biaxial (-), a=1.625, b=1.68, g=1.706, bire=0.0810, 2V(Calc)=66, 2V(Meas)=57. |
| Calculated Properties of Posnjakite Electron Density: |
Bulk Density (Electron Density)=3.30 gm/cc |
note: Specific Gravity of Posnjakite =3.40 gm/cc. Fermion Index: |
Fermion Index = 0.00069355 |
Boson Index = 0.99930645 Photoelectric: |
PEPosnjakite = 23.94 barns/electron |
U=PEPosnjakite x rElectron Density= 78.94 barns/cc. Radioactivity: |
GRapi = 0 (Gamma Ray American Petroleum Institute Units) |
Posnjakite is Not Radioactive | Posnjakite Classification Dana Class: |
31.04.01.01 (31)Hydrated Sulfates Containing Hydroxyl or Halogen |
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(31.04)where (A+ B++)4 (XO4) Zq·x(H2O) |
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(31.04.01)Dana Group |
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Strunz Class: |
07.DD.10 07 - SULFATES (SELENATES, TELLURATES) |
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07.D - Sulfates (selenates, etc.) with additional anions, with H2O |
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07.DD -With only medium-sized cations; sheets of edge-sharing octahedra |
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| Other Posnjakite Information References: |
NAME( Duda&Rejl90) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990) |
See Also: |
Links to other databases for Posnjakite : |
1 - Alkali-Nuts(English) 2 - Alkali-Nuts(Francais) 3 - Am. Min. Crystal Structure Database 4 - Athena 5 - EUROmin Project 6 - Ecole des Mines de Paris 7 - GeoScienceWorld 8 - Google Images 9 - Google Scholar 10 - Handbook of Mineralogy (MinSocAm) 11 - Handbook of Mineralogy (UofA) 12 - MinDAT 13 - Mineralienatlas (Deutsch) 14 - Online Mineral Museum 15 - QUT Mineral Atlas 16 - Ruff.Info 17 - WWW-MINCRYST Search for Posnjakite using: Visit our Advertisers for Posnjakite : A Bijoux Google Search for PosnjakiteAdam's Minerals Google Search for Posnjakite Cape Minerals Google Search for Posnjakite Dakota Matrix Minerals Google Search for Posnjakite Excalibur Mineral Corp. Google Search for Posnjakite Exceptional Minerals Google Search for Posnjakite John Betts Fine Minerals Search for Posnjakite McDougall Minerals Google Search for Posnjakite Mineral News Website Link Rock and Mineral Shows Google Search for Posnjakite Weinrich Minerals, Inc. Google Search for Posnjakite Ask about Posnjakite here : Print or Cut-and-Paste your Posnjakite Specimen Label here :
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