Mineralogy Database

Gratonite Mineral Data

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General Gratonite Information

Help on Chemical  Formula: Chemical Formula: Pb9As4S15
Help on Composition: Composition: Molecular Weight = 2,645.48 gm
   Arsenic  11.33 %  As
   Lead     70.49 %  Pb
   Sulfur   18.18 %  S
           ______ 
           100.00 % 
Help on Empirical Formula: Empirical Formula: Pb9As4S15
Help on Environment: Environment: In vugs in hydrothermal copper ores.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1939
Help on Locality: Locality: In the Excelsior mine, Cerro de Pasco, Peru, in large crystals. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: For Louis Carly Graton (1880-1970), Professor of Economic Geology, Harvard University, Cambridge, Massachusetts, USA.
Help on Name Pronunciation: Name Pronunciation: Gratonite + Pronunciation Say GRATONITE
Help on Synonym: Synonym: ICSD 18097
  PDF 44-1412
 

Gratonite Image

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  Gratonite

Comments: Crystal cluster of gratonite. The largest crystal is 2.5 mm across.
Location: Excelsior mine, Cerro de Pasco, Pasco dept., Peru. Scale: 1.5 x 1 cm.
© John Veevaert

Gratonite Crystallography

Help on Axial Ratios: Axial Ratios: a:c = 1:0.4402
Help on Cell Dimensions: Cell Dimensions: a = 17.701, c = 7.792, Z = 3; V = 2,114.34 Den(Calc)= 6.23
Help on Crystal System: Crystal System: Trigonal - Ditrigonal Pyramidal H-M Symbol (3m) Space Group: R 3m
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 3.43(1), 3.75(0.6), 2.734(0.5),
Help on Forms: Forms:

Mouse
Dbl Clk - Start-Stop Rotation
RMB - Cycle Display Modes
Drag1 - Manipulate Crystal
Drag2 - Resize

Keyboard
S - Stereo
I - Indicies
<space> - Start-Stop Rotation
F - Fit to Screen
M - Menu

Help on Above

Forms: ( 1 0 1) ( 4 0 1) ( 0 0 1) ( 1 1 0) ( 1 0 0) ( 0 2 1)

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Physical Properties of Gratonite

Help on Cleavage: Cleavage: None
Help on Color: Color: Lead gray, Dark lead gray.
Help on Density: Density: 6.22
Help on Diaphaneity: Diaphaneity: Opaque
Help on Fracture: Fracture: Brittle - Generally displayed by glasses and most non-metallic minerals.
Help on Hardness: Hardness: 2.5 - Finger Nail
Help on Luster: Luster: Metallic
Help on Streak: Streak: black
 

Optical Properties of Gratonite

Help on Optical Data: Optical Data:
Help on RL Color: RL Color: White, distinctly yellow against galena.
Help on RL Pleochroism: RL Pleochroism: Very weak.
Help on Reflectivity Reflectivity
Standardized Intensity (100%) Reflection Spectra of Gratonite in Air
λ R1 R2  ∑ R1(λ)   ∑ R2(λ) 
 400 nm   36.90   37.80 
   
 420 nm   36.30   37.20 
 440 nm   35.70   36.60 
 460 nm   35.30   36.10 
 480 nm   35.10   35.70 
 500 nm   34.80   35.40 
 520 nm   34.50   35.00 
 540 nm   34.20   34.80 
 560 nm   34.10   34.60 
 580 nm   34.00   34.50 
 600 nm   33.90   34.50 
 620 nm   33.80   34.40 
 640 nm   33.70   34.20 
 660 nm   33.50   33.80 
 680 nm   33.00   33.40 
 700 nm   32.40   32.70 
Calculated Relative Intensity Colors of Gratonite in Air
Relative
Intensity
   0%   30%   60%   90% 100% 120% 150% 180% 210% 240% 260%
R1                      
R2                      
 

Calculated Properties of Gratonite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=5.23 gm/cc
note: Specific Gravity of Gratonite =6.23 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.15
Boson Index = 0.85
Help on Photoelectric: Photoelectric: PEGratonite =1,299.32 barns/electron
U=PEGratonite x rElectron Density=6,792.88 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Gratonite is Not Radioactive
 

Gratonite Classification

Help on  Dana Class: Dana Class: 03.03.02.01 (03)Sulfides - Sulfosalts
  (03.03)where 3 < z/y < 4 - (A+)i (A++)j [By Cz], A=metals, B=semi-metals, C=non-metals
  (03.03.02)Dana Group
 
03.03.02.01 Gratonite Pb9As4S15 R 3m 3m
Help on  Strunz Class: Strunz Class: 02.JB.55 02 - SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulf
  02.J - Sulfosalts of PbS Archetype
  02.JB -Galena derivatives, with Pb
 
02.JB.55 Gratonite Pb9As4S15 R 3m 3m
 

Other Gratonite 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 Gratonite :
1 - Am. Min. Crystal Structure Database
2 - Amethyst Galleries' Mineral Gallery
3 - Athena
4 - EUROmin Project
5 - Ecole des Mines de Paris
6 - GeoScienceWorld
7 - Google Images
8 - Google Scholar
9 - Handbook of Mineralogy (MinSocAm)
10 - Handbook of Mineralogy (UofA)
11 - HyperPhysics
12 - MinDAT
13 - Mineralienatlas (Deutsch)
14 - Online Mineral Museum
15 - QUT Mineral Atlas
16 - Ruff.Info

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Print or Cut-and-Paste your Gratonite Specimen Label here :

Gratonite

Pb9As4S15
Dana No: 03.03.02.01 Strunz No: 02.JB.55
Locality:

 

Notes:

 

 
   
 


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