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Grechishchevite Mineral Data

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General Grechishchevite Information

Help on Chemical  Formula: Chemical Formula: Hg3S2(Br,Cl,I)2
Help on Composition: Composition: Molecular Weight = 817.84 gm
   Mercury   73.58 %  Hg   76.51 % Hg2O
   Sulfur     7.84 %  S     7.84 % S2-
               -   %  S    -3.91 % -O=S 
   Iodine     6.21 %  I     6.21 % I
               -   %   I    -0.39 % -O=I2    
   Bromine    9.77 %  Br    9.77 % Br
               -   %   Br   -0.98 % -O=Br2   
   Chlorine   2.60 %  Cl    2.60 % Cl
               -   %   Cl   -0.59 % -O=Cl2   
            ______        ______ 
            100.00 %       97.07 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Hg3S2BrCl0.6I0.4
Help on Environment: Environment: In the oxidation zone in fractures of a mercury deposit.
Help on IMA Status: IMA Status: Approved IMA 1990
Help on Locality: Locality: Arzak and Kadyrel mercury deposits, Tuva, Siberia, Russia. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Oleg Konstantinovich Grechishchev, Russian engineering geologist, long-time student of mercury ores from Tuva, Siberia.
Help on Name Pronunciation: Name Pronunciation: Grechishchevite + Pronunciation Say GRECHISHCHEVITE

Grechishchevite Image

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Comments: Red grechishchevite coatings on calcite.
Location: Kadyrel' Hg occurrence, Oorash-Khem River Valley, Uyuk Range, Pii-Khem District, Tuva Republic, Eastern-Siberian Region, Russia. Scale: Picture Size 2 mm.
© Jeff Weissman / Photographic Guide to Mineral Species

Grechishchevite Crystallography

Help on Axial Ratios: Axial Ratios: a:c = 1:0.65671
Help on Cell Dimensions: Cell Dimensions: a = 13.225, c = 8.685, Z = 8; V = 1,519.01 Den(Calc)= 7.15
Help on Crystal System: Crystal System: Tetragonal Space Group: P 42m-,P 4m2,P 4mm,P 4/mmm
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 2.65(1), 3.02(0.6), 3.95(0.6),

Physical Properties of Grechishchevite

Help on Cleavage: Cleavage: {???} Good
Help on Color: Color: Brownish black, Orange, Reddish orange.
Help on Density: Density: 7.16
Help on Diaphaneity: Diaphaneity: Transparent
Help on Habit: Habit: Microscopic Crystals - Crystals visible only with microscopes.
Help on Habit: Habit: Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).
Help on Hardness: Hardness: 2.5 - Finger Nail
Help on Luster: Luster: Vitreous - Adamantine
Help on Streak: Streak: deep yellow

Optical Properties of Grechishchevite

Help on Dichroism (e): Dichroism (e): yellow.
Help on Dichroism (w): Dichroism (w): straw yellow.
Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.091 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= 0.09 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1399,KPDmeas= 0.1397,KC= 0.1537
Ncalc = 2.1
Help on Optical Data: Optical Data: Uniaxial (+), w=2, e=2, bire=0.0000.
Help on RL Color: RL Color: Gray wihte with strong internal orange reflections.
Help on Reflectivity Reflectivity
Standardized Intensity (100%) Reflection Spectra of Grechishchevite in Air
λ R1 R2  ∑ R1(λ)   ∑ R2(λ) 
 436 nm   22.80   19.20 
 460 nm   24.50   22.20 
 500 nm   21.40   18.90 
 546 nm   19.80   17.30 
 590 nm   18.80   16.50 
 620 nm   18.90   16.70 
 656 nm   18.10   15.90 
Calculated Relative Intensity Colors of Grechishchevite in Air
   0%   60% 100% 120% 180% 240% 300% 360% 420% 480% 530%

Calculated Properties of Grechishchevite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=5.92 gm/cc
note: Specific Gravity of Grechishchevite =7.15 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.22
Boson Index = 0.78
Help on Photoelectric: Photoelectric: PEGrechishchevite =1,293.80 barns/electron
U=PEGrechishchevite x rElectron Density=7,655.34 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Grechishchevite is Not Radioactive

Grechishchevite Classification

Help on  Dana Class: Dana Class: (10)Oxyhalides and Hydroxyhalides
  (10.03)where (A)3 (O,OH)2 Xq
  (10.03.05)Dana Group Grechishchevite Hg3S2(Br,Cl,I)2 P 42m-,P 4m2,P 4mm,P 4/mmm Tetra
Help on  Strunz Class: Strunz Class: 02.FC.15c 02 - SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulf
  02.F - Sulfides of Arsenic, Alkalies; Sulfides with Halide, Oxide, Hydroxide, H2O
  02.FC -With Cl, Br, I (halide-sulfides)
02.FC.15c Grechishchevite Hg3S2(Br,Cl,I)2 P 42m-,P 4m2,P 4mm,P 4/mmm Tetra

Other Grechishchevite Information

Help on References: References: NAME( Dana8) PHYS. PROP.(Dana8) OPTIC PROP.(AntBidBlaNic3)
Help on See Also: See Also: Links to other databases for Grechishchevite :
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: 02.FC.15c





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