Mineralogy Database

Polybasite Mineral Data

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General Polybasite Information

Help on Chemical  Formula: Chemical Formula: [Ag9CuS4] [(Ag,Cu)6(Sb,As)2S7]
Help on Composition: Composition: Molecular Weight = 2,154.03 gm
   Copper     8.85 %  Cu
   Silver    65.10 %  Ag
   Antimony   7.07 %  Sb
   Arsenic    2.61 %  As
   Sulfur    16.38 %  S
            ______ 
            100.00 % 
Help on Empirical Formula: Empirical Formula: Ag9CuS4Ag4Cu2Sb1.25As0.75S7
Help on Environment: Environment: In silver viens of low to moderate temperature of formation.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1829
Help on Locality: Locality: Common world wide. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: From the Greek, poly, "many" and basis, "a base" in allusion to the basic character of the compound.
Help on Name Pronunciation: Name Pronunciation: Polybasite + Pronunciation Say POLYBASITE
Help on Synonym: Synonym: Polybasite-M2a2b2c - Suggested nomenclature from AmMin v92:918
  Polybasite-T2ac - Suggested nomenclature from AmMin v92:918
 

Polybasite Image

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  Polybasite

Comments: Lustrous, metallic steel-gray rosette of polybasite crystals.
Location: Guanajuato, Mexico. Scale: 18 x 16 x 8 mm.
© Dan Weinrich

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  Polybasite

Comments: Cyclic-twinned polybasite grain embedded in matrix..
Location: The Zaca mine, Alpine Co., California, USA. Scale: Grainsize .75 mm.
© Tom Loomis / Dakota Matrix

Polybasite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =1.732:1:1.5842
Help on Cell Dimensions: Cell Dimensions: a = 26.12, b = 15.08, c = 23.89, Z = 16; beta = 90° V = 9,410.02 Den(Calc)= 6.08
Help on Crystal System: Crystal System: Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/m
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 3(1), 3.19(0.9), 2.88(0.8),
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: ( 2 0 1) ( 1 1 1) ( 0 0 1)

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Physical Properties of Polybasite

Help on Cleavage: Cleavage: {001} Poor
Help on Color: Color: Black, Dark ruby red.
Help on Density: Density: 4.6 - 5, Average = 4.8
Help on Diaphaneity: Diaphaneity: Opaque
Help on Fracture: Fracture: Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern.
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 Habit: Habit: Pseudo Hexagonal - Crystals show a hexagonal outline.
Help on Hardness: Hardness: 2.5-3 - Finger Nail-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 Polybasite

Help on Optical Data: Optical Data: NCalc= 1.84 - from Gladstone-Dale relationship (KC = 0.1378) where Ncalc=Dcalc*KC+1
NCalc= 1.66 - from Gladstone-Dale relationship (KC = 0.1378) where Ncalc=Dmeas*KC+1
Help on Reflectivity Reflectivity
Standardized Intensity (100%) Reflection Spectra of Polybasite in Air
λ R1 R2  ∑ R1(λ)   ∑ R2(λ) 
 400 nm   33.90   32.50 
   
 420 nm   33.60   32.80 
 440 nm   33.00   33.90 
 460 nm   31.90   33.80 
 480 nm   32.40   34.00 
 500 nm   31.90   33.80 
 520 nm   31.30   33.40 
 540 nm   30.80   32.80 
 560 nm   30.50   32.20 
 580 nm   30.20   31.70 
 600 nm   29.80   31.10 
 620 nm   29.30   30.50 
 640 nm   29.10   29.30 
 660 nm   27.30   29.10 
 680 nm   27.20   28.40 
 700 nm   26.90   27.80 
Calculated Relative Intensity Colors of Polybasite in Air
Relative
Intensity
   0%   40%   80% 100% 120% 160% 200% 240% 280% 300%
R1                    
R2                    
 

Calculated Properties of Polybasite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=5.43 gm/cc
note: Specific Gravity of Polybasite =6.08 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0012281379
Boson Index = 0.9987718621
Help on Photoelectric: Photoelectric: PEPolybasite = 196.28 barns/electron
U=PEPolybasite x rElectron Density=1,066.49 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Polybasite is Not Radioactive
 

Polybasite Classification

Help on  Dana Class: Dana Class: 03.01.07.02 (03)Sulfides - Sulfosalts
  (03.01)where z/y > 4 - (A+)i (A++)j [By Cz], A=metals, B=semi-metals, C=non-metals
  (03.01.07)Polybasite group
 
03.01.07.01 Arsenpolybasite [Ag9CuS4][(Ag,Cu)6(As,Sb)2S7] C 2/m 2/m
 
03.01.07.02 Polybasite [Ag9CuS4][(Ag,Cu)6(Sb,As)2S7] C 2/m 2/m
 
03.01.07.03 Selenopolybasite! [(Ag,Cu)6(Sb,As)2(S,Se)7][Ag9Cu(S,Se)2Se2] P 3m1 3m
 
03.01.07.04 Cupropolybasite! [Cu6Sb2S7][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 Polybasite Information

Help on References: References: NAME( Ford32) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic1)
Help on See Also: See Also: Links to other databases for Polybasite :
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 - MinDAT
12 - Mineralienatlas (Deutsch)
13 - Online Mineral Museum
14 - Philatelic Mineralogy
15 - QUT Mineral Atlas
16 - Ruff.Info

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

Polybasite

[Ag9CuS4] [(Ag,Cu)6(Sb,As)2S7]
Dana No: 03.01.07.02 Strunz No: 02.GB.15
Locality:

 

Notes:

 

 
   
 


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