Mineralogy Database

Guettardite Mineral Data

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General Guettardite Information

Help on Chemical  Formula: Chemical Formula: Pb(Sb,As)2S4
Help on Composition: Composition: Molecular Weight = 536.82 gm
   Antimony  24.95 %  Sb
   Arsenic   12.56 %  As
   Lead      38.60 %  Pb
   Sulfur    23.89 %  S
            ______ 
            100.00 % 
Help on Empirical Formula: Empirical Formula: PbSb1.1As0.9S4
Help on Environment: Environment: Low-temperature hydrothermal origin, in marbles.
Help on IMA Status: IMA Status: Approved IMA 1967
Help on Locality: Locality: At Madoc, Ontario, Canada. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Jean Etienne Guettard (17-15-1786), French geologist.
Help on Name Pronunciation: Name Pronunciation: Guettardite + Pronunciation Say GUETTARDITE
Help on Synonym: Synonym: IMA1966-018
 

Guettardite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =2.5289:1:1.1028
Help on Cell Dimensions: Cell Dimensions: a = 20.095, b = 7.946, c = 8.763, Z = 8; beta = 101.2° V = 1,372.58 Den(Calc)= 5.20
Help on Crystal System: Crystal System: Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 21/a
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 3.52(1), 2.795(0.9), 4.19(0.5),
 

Physical Properties of Guettardite

Help on Cleavage: Cleavage: {001} Perfect
Help on Color: Color: Grayish black.
Help on Density: Density: 5.31
Help on Diaphaneity: Diaphaneity: Opaque
Help on Fracture: Fracture: Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.
Help on Habit: Habit: Acicular - Occurs as needle-like crystals.
Help on Habit: Habit: Anhedral Grains - Granular minerals without the expression of crystal shapes
Help on Hardness: Hardness: 4 - Fluorite
Help on Luster: Luster: Metallic
Help on Streak: Streak: brownish
 

Optical Properties of Guettardite

Help on RL Color: RL Color: White with reddish internal reflections.
Help on RL Pleochroism: RL Pleochroism: Relatively strong.
Help on Reflectivity Reflectivity
Standardized Intensity (100%) Reflection Spectra of Guettardite in Air
λ R1 R2  ∑ R1(λ)   ∑ R2(λ) 
 470 nm   37.60   42.60 
   
 546 nm   36.10   41.20 
 589 nm   34.80   39.30 
 650 nm   33.80   36.70 
Calculated Relative Intensity Colors of Guettardite in Air
Relative
Intensity
   0%   30%   60%   90% 100% 120% 150% 180% 210% 240% 260%
R1                      
R2                      
 

Calculated Properties of Guettardite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=4.49 gm/cc
note: Specific Gravity of Guettardite =5.20 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.08
Boson Index = 0.92
Help on Photoelectric: Photoelectric: PEGuettardite = 781.87 barns/electron
U=PEGuettardite x rElectron Density=3,511.20 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Guettardite is Not Radioactive
 

Guettardite Classification

Help on  Dana Class: Dana Class: 03.07.08.02 (03)Sulfides - Sulfosalts
  (03.07)where z/y = 2 - (A+)i (A++)j [By Cz], A=metals, B=semi-metals, C=non-metals
  (03.07.08)Sartorite Group
 
03.07.08.01 Sartorite PbAs2S4 P 21/c 2/m
 
03.07.08.02 Guettardite Pb(Sb,As)2S4 P 21/a 2/m
 
03.07.08.03 Twinnite Pb(Sb,As)2S4 P1 1
 
03.07.08.04 Marumoite! Pb32As40S92 P 21 2
Help on  Strunz Class: Strunz Class: 02.HC.05a 02 - SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulf
  02.H - Sulfosalts of SnS Archetype
  02.HC -With only Pb
 
02.HC.05a Guettardite Pb(Sb,As)2S4 P 21/a 2/m
 
02.HC.05a Sartorite PbAs2S4 P 21/c 2/m
 
02.HC.05a Twinnite Pb(Sb,As)2S4 P1 1
 

Other Guettardite Information

Help on References: References: NAME( AntBidBlaNic1) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic1)
Help on See Also: See Also: Links to other databases for Guettardite :
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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Print or Cut-and-Paste your Guettardite Specimen Label here :

Guettardite

Pb(Sb,As)2S4
Dana No: 03.07.08.02 Strunz No: 02.HC.05a
Locality:

 

Notes:

 

 
   
 


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