Benjaminite Mineral Data (original) (raw)
General Benjaminite Information
Chemical Formula:
(Ag,Cu)3(Bi,Pb)7S12
Composition:
Molecular Weight = 2,134.46 gm
Copper 2.23 % Cu
Silver 11.37 % Ag
Bismuth 48.95 % Bi
Lead 19.41 % Pb
Sulfur 18.03 % S
______
100.00 %
Empirical Formula:
Ag2.25Cu0.75Bi5Pb2S12
Environment:
In a quartz vein near the contact of a soda-granite and an intrusive rhyolite.
IMA Status:
Valid Species (Pre-IMA) 1924
Locality:
Outlaw Mine, 12 miles north of Manhattan, Nye Co. Nevada, USA. Link to MinDat.org Location Data.
Name Origin:
For Dr. Marcus Benjamin (1857-1932), of the U.S. National Museum.
Name Pronunciation:
Benjaminite + Pronunciation 
Synonym:
ICSD 100734
PDF 29-577
Benjaminite Image
Images:
Benjaminite Crystallography
Axial Ratios:
a:b:c =3.2754:1:4.9898
Cell Dimensions:
a = 13.246, b = 4.044, c = 20.179, Z = 2; beta = 103.21° V = 1,052.32 Den(Calc)= 6.74
Crystal System:
Monoclinic - PrismaticH-M Symbol (2/m) Space Group: C 2/c
X Ray Diffraction:
By Intensity(I/Io): 2.851(1), 3.427(0.8), 3.539(0.8),
Crystal Structure:
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| | Makovicky E , Mumme W G , The Canadian Mineralogist , 17 (1979) p.607-618, The crystal structure of benjaminite Cu.5Pb.4Ag2.3Bi6.8S12 | | ---------------------------------------------------------------------------------------------------------------------------------------- |
Physical Properties of Benjaminite
Cleavage:
{hk0} Fair
Color:
Grayish yellow, Copper.
Density:
6.7
Diaphaneity:
Opaque
Hardness:
3.5 - Copper Penny
Luminescence:
Non-fluorescent.
Luster:
Metallic
Magnetism:
Nonmagnetic
Optical Properties of Benjaminite
RL Anisotrophism:
Strong.
RL Color:
Creamy white to very pale brownish.
Reflectivity
Standardized Intensity (100%) Reflection Spectra of Benjaminite in Air
| λ | R1 | R 2 |  |
∑ R1(λ) | ∑ R2(λ) |
|---|---|---|---|---|---|
| 400 nm | 44.20 | 47.20 |  |
||
| 420 nm | 44.80 | 47.80 |  |
||
| 440 nm | 45.20 | 48.60 |  |
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| 460 nm | 45.20 | 49.00 |  |
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| 480 nm | 45.00 | 49.20 |  |
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| 500 nm | 44.80 | 49.20 |  |
||
| 520 nm | 44.50 | 49.00 |  |
||
| 540 nm | 44.00 | 48.60 |  |
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| 560 nm | 43.60 | 48.00 |  |
||
| 580 nm | 43.30 | 47.60 |  |
||
| 600 nm | 43.10 | 47.20 |  |
||
| 620 nm | 43.00 | 46.80 |  |
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| 640 nm | 42.80 | 46.30 |  |
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| 660 nm | 42.70 | 45.90 |  |
||
| 680 nm | 42.60 | 45.60 |  |
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| 700 nm | 42.50 | 45.20 |  |
Calculated Relative Intensity Colors of Benjaminite in Air
| RelativeIntensity | 0% | 30% | 60% | 90% | 100% | 120% | 150% | 180% | 210% |
|---|---|---|---|---|---|---|---|---|---|
| R1 | |||||||||
| R2 |
Calculated Properties of Benjaminite
Electron Density:
Bulk Density (Electron Density)=5.67 gm/cc
note: Specific Gravity of Benjaminite =6.74 gm/cc.
Fermion Index:
Fermion Index = 0.04
Boson Index = 0.96
Photoelectric:
PEBenjaminite =1,322.77 barns/electron
U=PEBenjaminite x rElectron Density=7,505.95 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Benjaminite is Not Radioactive
Benjaminite Classification
Dana Class:
03.08.10.03 (03)Sulfides - Sulfosalts
(03.08)where 1 < z/y <2 - (A+)i (A++)j [By Cz], A=metals, B=semi-metals, C=non-metals
(03.08.10)Pavonite Group (Monoclinic: C/2c bismuth sulfosalts)
03.08.10.01 Pavonite (Ag,Cu)(Bi,Pb)3S5 C 2/c 2/m
03.08.10.02 Makovickyite Ag1.5Bi5.5S9 C 2/c 2/m
03.08.10.03 Benjaminite (Ag,Cu)3(Bi,Pb)7S12 C 2/c 2/m
03.08.10.04 Mummeite Cu0.58Ag3.11Pb1.10Bi6.65S13 C 2/c 2/m
03.08.10.05 Borodaevite Ag5(Bi,Sb)9S16 C 2/c 2/m
03.08.10.06 Cupropavonite AgPbCu2Bi5S10 C 2/c 2/m
03.08.10.07 Cupromakovickyite! Cu4AgPb2Bi9S18 C 2/m 2/m
03.08.10.08 Kudriavite! (Cd,Pb)Bi2S4 C 2/m 2/m
03.08.10.09 IMA2008-058! Ag5Bi13S22 C 2/m 2/m
03.08.10.10 IMA2005-036! Cu8Pb4Ag3Bi19S38 C 2/m 2/m
Strunz Class:
02.JA.05e 02 - SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulf
02.J - Sulfosalts of PbS Archetype
02.JA -Galena derivatives with little or no Pb
02.JA.05e Benjaminite (Ag,Cu)3(Bi,Pb)7S12 C 2/c 2/m
Other Benjaminite Information
References:
NAME( AntBidBlaNic1) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic1)
See Also:
Links to other databases for Benjaminite :
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
15 - WWW-MINCRYST
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Print or Cut-and-Paste your Benjaminite Specimen Label here :
Benjaminite
(Ag,Cu)3(Bi,Pb)7S12
Dana No: 03.08.10.03 Strunz No: 02.JA.05e
Locality:
Notes: