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Coquandite Mineral Data

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General Coquandite Information

Help on Chemical  Formula: Chemical Formula: Sb6O8(SO4)•(H2O)
Help on Composition: Composition: Molecular Weight = 972.57 gm
   Antimony  75.11 %  Sb   89.92 % Sb2O3
   Hydrogen   0.21 %  H     1.85 % H2O
   Sulfur     3.30 %  S     8.23 % SO3
   Oxygen    21.39 %  O
            ______        ______ 
            100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Sb6O8(SO4)•(H2O)
Help on Environment: Environment: Probably produced by action of H2SO4 on stibnite, in a stibnite vein in silicified limestone
Help on IMA Status: IMA Status: Approved IMA 1992
Help on Locality: Locality: Cetine mine, 20 km southwest of Siena, and the Pereta mine, Scansano, Tuscany, Italy. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Henri-Jean-Baptiste Coquand (1813-1881), Professor of Geology and Mineralogy, University of Marseilles, Marseilles, France
Help on Synonym: Synonym: IMA1991-024

Coquandite Image

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Comments: Silky coquandite with stibnite.
Location: Pereta mine, Grosseto, Tuscany, Italy. Scale: Picture size 5 mm.
© Thomas Witzke / Abraxas-Verlag

Coquandite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.384:1:0.38
Help on Cell Dimensions: Cell Dimensions: a = 11.434, b = 29.77, c = 11.314, Z = 12; alpha = 91.073°, beta = 119.245°, gamma = 92.82° V = 3,355.64 Den(Calc)= 5.77
Help on Crystal System: Crystal System: Triclinic - Pinacoidal H-M Symbol ( 1) Space Group: P1
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 3.092(1), 3.304(0.93), 6.81(0.67),

Physical Properties of Coquandite

Help on Cleavage: Cleavage: {???} Perfect
Help on Color: Color: Colorless, White.
Help on Diaphaneity: Diaphaneity: Transparent to Translucent
Help on Hardness: Hardness: 3-4 - Calcite-Fluorite
Help on Luster: Luster: Adamantine
Help on Streak: Streak: white

Optical Properties of Coquandite

Help on Gladstone-Dale: Gladstone-Dale: CI calc= 0.081 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1869,KC= 0.2034
Ncalc = 2.18
Help on Optical Data: Optical Data: Biaxial (+), b=2.08, 2V(Meas)=80-85.

Calculated Properties of Coquandite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=5.09 gm/cc
note: Specific Gravity of Coquandite =5.78 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0003502393
Boson Index = 0.9996497607
Help on Photoelectric: Photoelectric: PECoquandite = 251.19 barns/electron
U=PECoquandite x rElectron Density=1,277.87 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Coquandite is Not Radioactive

Coquandite Classification

Help on  Dana Class: Dana Class: (30)Anhydrous Sulfates Containing Hydroxyl or Halogen
  (30.01)where (A B)m (XO4)p Zq where m:p>2:1
  (30.01.18)Dana Group Coquandite Sb6O8(SO4)•(H2O) P1 1
Help on  Strunz Class: Strunz Class: 07.DE.35 07 - SULFATES (SELENATES, TELLURATES)
  07.D - Sulfates (selenates, etc.) with additional anions, with H2O
  07.DE -With only medium-sized cations; unclassified
07.DE.35 Coquandite Sb6O8(SO4)•(H2O) P1 1

Other Coquandite Information

Help on References: References: NAME( AntBidBlaNic5) PHYS. PROP.(37th List of New Min.,Min. Mag.,1996) OPTIC PROP.(37th List of New Min.,Min. Mag.,19)
Help on See Also: See Also: Links to other databases for Coquandite :
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

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Dana No: Strunz No: 07.DE.35





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