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Pearceite Mineral Data

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General Pearceite Information

Help on Chemical  Formula: Chemical Formula: [Ag9CuS4] [(Ag,Cu)6(As,Sb)2S7]
Help on Composition: Composition: Molecular Weight = 2,096.80 gm
   Copper    11.64 %  Cu
   Silver    62.50 %  Ag
   Antimony   4.82 %  Sb
   Arsenic    4.22 %  As
   Sulfur    16.82 %  S
            ______ 
            100.00 % 
Help on Empirical Formula: Empirical Formula: Ag12.15Cu3.84As1.18Sb0.83S11
Help on Environment: Environment: The arsenic analog of polybasite.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1896
Help on Locality: Locality: Aspen, Colorado. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named after the American chemist, R. Pearce (1837-1927).
Help on Name Pronunciation: Name Pronunciation: Pearceite + Pronunciation Say PEARCEITE
Help on Synonym: Synonym: Pearceite-Tac - Suggested nomenclature from AmMin v92:918
 

Pearceite Image

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  Pearceite

Comments: Crystals of metallic pearceite to 0.75 mm scattered in vug.
Location: Sarbaiskoe, Kazakhstan. Scale: 4x3x3 cm.
© Tom Loomis / Dakota Matrix

Pearceite Crystallography

Help on Axial Ratios: Axial Ratios: a:c = 1:1.60921
Help on Cell Dimensions: Cell Dimensions: a = 7.3876, c = 11.8882, Z = 1; V = 561.89 Den(Calc)= 6.20
Help on Crystal System: Crystal System: Trigonal - Hexagonal Scalenohedral H-M Symbol (3 2/m) Space Group: P 3m1
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 3(1), 2.84(0.9), 3.11(0.5),
Help on Forms: Forms:

Mouse
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Drag1 - Manipulate Crystal
Drag2 - Resize

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Help on Above

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

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Physical Properties of Pearceite

Help on Cleavage: Cleavage: {001} Poor
Help on Color: Color: Black.
Help on Density: Density: 6.15
Help on Diaphaneity: Diaphaneity: Opaque to subtranslucent
Help on Fracture: Fracture: Conchoidal - Irregular - Irregular fracture producing small, conchoidal fragments.
Help on Habit: Habit: Granular - Generally occurs as anhedral to subhedral crystals in matrix.
Help on Habit: Habit: Massive - Granular - Common texture observed in granite and other igneous rock.
Help on Hardness: Hardness: 3 - Calcite
Help on Luminescence: Luminescence: Non-fluorescent.
Help on Luster: Luster: Sub Metallic
Help on Magnetism: Magnetism: Nonmagnetic
Help on Streak: Streak: reddish black
 

Optical Properties of Pearceite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -1.009 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= -0.993 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2742,KPDmeas= 0.2764,KC= 0.1376
Ncalc = 1.85
Help on Optical Data: Optical Data: Biaxial (?), a=2.7
Help on RL Anisotrophism: RL Anisotrophism: Moderate, often dark violet.
Help on RL Color: RL Color: White, with very dark red internal reflections.
Help on RL Pleochroism: RL Pleochroism: Very weak in air, fair in oil.
Help on Reflectivity Reflectivity
Standardized Intensity (100%) Reflection Spectra of Pearceite in Air
λ R1 R2  ∑ R1(λ)   ∑ R2(λ) 
 400 nm   34.80   34.30 
   
 420 nm   34.20   34.20 
 440 nm   33.40   34.10 
 460 nm   32.50   33.80 
 480 nm   31.50   33.20 
 500 nm   30.60   32.80 
 520 nm   29.80   32.50 
 540 nm   29.30   32.30 
 560 nm   29.00   32.00 
 580 nm   29.00   31.70 
 600 nm   29.10   31.20 
 620 nm   29.10   30.70 
 640 nm   28.90   30.20 
 660 nm   28.60   29.80 
 680 nm   28.00   29.30 
 700 nm   27.40   29.10 
Calculated Relative Intensity Colors of Pearceite in Air
Relative
Intensity
   0%   40%   80% 100% 120% 160% 200% 240% 280% 300%
R1                    
R2                    
 

Calculated Properties of Pearceite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=5.56 gm/cc
note: Specific Gravity of Pearceite =6.20 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0012616575
Boson Index = 0.9987383425
Help on Photoelectric: Photoelectric: PEPearceite = 184.23 barns/electron
U=PEPearceite x rElectron Density=1,023.75 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Pearceite is Not Radioactive
 

Pearceite Classification

Help on  Dana Class: Dana Class: 03.01.08.01 (03)Sulfides - Sulfosalts
  (03.01)where z/y > 4 - (A+)i (A++)j [By Cz], A=metals, B=semi-metals, C=non-metals
  (03.01.08)Pearceite group
 
03.01.08.01 Pearceite [Ag9CuS4][(Ag,Cu)6(As,Sb)2S7] P 3m1 3 2/m
 
03.01.08.02 Antimonpearceite [Ag9CuS4][(Ag,Cu)6(Sb,As)2S7] C 2/m 2/m
 
03.01.08.03 Cupropearceite [Cu6As2S7][Ag9CuS4] P 3m1 3 2/m
Help on  Strunz Class: Strunz Class: 02.GB.15 02 - SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulf
  02.G - Sulfarsenites, sulfantimonites, sulfbismuthites
  02.GB -Neso-sulfarsenites, etc
 
02.GB.15 Antimonpearceite [Ag9CuS4][(Ag,Cu)6(Sb,As)2S7] C 2/m 2/m
 
02.GB.15 Arsenpolybasite [Ag9CuS4][(Ag,Cu)6(As,Sb)2S7] C 2/m 2/m
 
02.GB.15 Polybasite [Ag9CuS4][(Ag,Cu)6(Sb,As)2S7] C 2/m 2/m
 
02.GB.15 Pearceite [Ag9CuS4][(Ag,Cu)6(As,Sb)2S7] P 3m1 3 2/m
 
02.GB.15 Cupropearceite [Cu6As2S7][Ag9CuS4] P 3m1 3 2/m
 
02.GB.15 Selenopolybasite! [(Ag,Cu)6(Sb,As)2(S,Se)7][Ag9Cu(S,Se)2Se2] P 3m1 3m
 
02.GB.15 Cupropolybasite! [Cu6Sb2S7][Ag9CuS4] P 3m1 3 2/m
 

Other Pearceite Information

Help on References: References: NAME( Duda&Rejl90) PHYS. PROP.(Dana8, AmMin 91:1953) OPTIC PROP.(AntBidBlaNic1)
Help on See Also: See Also: Links to other databases for Pearceite :
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 Pearceite Specimen Label here :

Pearceite

[Ag9CuS4] [(Ag,Cu)6(As,Sb)2S7]
Dana No: 03.01.08.01 Strunz No: 02.GB.15
Locality:

 

Notes:

 

 
   
 


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