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Comancheite Mineral Data

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General Comancheite Information

Help on Chemical  Formula: Chemical Formula: Hg13(Cl,Br)8O9
Help on Composition: Composition: Molecular Weight = 3,079.74 gm
   Mercury   84.67 %  Hg   91.43 % HgO
   Bromine    2.59 %  Br    2.59 % Br
               -   %   Br   -0.26 % -O=Br2   
   Chlorine   8.06 %  Cl    8.06 % Cl
               -   %   Cl   -1.82 % -O=Cl2   
   Oxygen     4.68 %  O
            ______        ______ 
            100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Hg13Cl7BrO9
Help on Environment: Environment: Encrusting calcite.
Help on IMA Status: IMA Status: Approved IMA 1981
Help on Locality: Locality: Mariposa mine, Terlingua district, Brewster County, Texas, USA. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for the Comanche Indians, who were the first miners in the Terligua district, using cinnabar for war paint.

Comancheite Image

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Comments: Small orange crystals of comancheite on matrix.
Location: Mariposa mine, Terlingua, Terlingua district, Brewster County, Texas, USA. Scale: Picture size 1.4 mm.
© Thomas Witzke / Abraxas-Verlag

Comancheite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.8507:1:0.3085
Help on Cell Dimensions: Cell Dimensions: a = 18.41, b = 21.64, c = 6.677, Z = 4; V = 2,660.07 Den(Calc)= 7.69
Help on Crystal System: Crystal System: Orthorhombic Space Group: Pnnm,Pnn2
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 2.669(1), 2.878(0.8), 5.68(0.7),

Physical Properties of Comancheite

Help on Cleavage: Cleavage: {001} Distinct, {110} Distinct
Help on Color: Color: Yellow, Orange red, Red.
Help on Density: Density: 7.7
Help on Fracture: Fracture: Brittle - Generally displayed by glasses and most non-metallic minerals.
Help on Habit: Habit: Acicular - Occurs as needle-like crystals.
Help on Habit: Habit: Stellate - Occurs as spherical, radial aggregates radiating from a "star" like point.
Help on Hardness: Hardness: 2 - Gypsum
Help on Luster: Luster: Vitreous - Resinous
Help on Streak: Streak: orange

Optical Properties of Comancheite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.29 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= 0.289 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1021,KPDmeas= 0.1019,KC= 0.1435
Ncalc = 2.1 - 2.11
Help on Optical Data: Optical Data: Biaxial (?), a=1.78, g=1.79, bire=0.0100

Calculated Properties of Comancheite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=6.32 gm/cc
note: Specific Gravity of Comancheite =7.69 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.25
Boson Index = 0.75
Help on Photoelectric: Photoelectric: PEComancheite =1,460.84 barns/electron
U=PEComancheite x rElectron Density=9,235.92 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Comancheite is Not Radioactive

Comancheite Classification

Help on  Dana Class: Dana Class: (10)Oxyhalides and Hydroxyhalides
  (10.05)where Am (O,OH)p Xq
  (10.05.05)Dana Group Comancheite Hg13(Cl,Br)8O9 Pnnm,Pnn2 Ortho
Help on  Strunz Class: Strunz Class: 03.DD.65 03 - HALIDES
  03.D - Oxyhalides, Hydroxyhalides and Related Double Halides
  03.DD -With Hg
03.DD.65 Comancheite Hg13(Cl,Br)8O9 Pnnm,Pnn2 Ortho

Other Comancheite Information

Help on References: References: NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Dana8)
Help on See Also: See Also: Links to other databases for Comancheite :
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: 03.DD.65





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