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Guettardite Mineral Data
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General Guettardite Information
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 Chemical Formula: |
Pb(Sb,As)2S4 |
| Composition: |
Molecular Weight = 536.82 gm |
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Antimony 24.95 % Sb |
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Arsenic 12.56 % As |
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Lead 38.60 % Pb |
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Sulfur 23.89 % S |
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______ |
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100.00 % |
| Empirical Formula: |
PbSb1.1As0.9S4 |
| Environment: |
Low-temperature hydrothermal origin, in marbles. |
| IMA Status: |
Approved IMA 1967 |
| Locality: |
At Madoc, Ontario, Canada. Link to MinDat.org Location Data. |
| Name Origin: |
Named for Jean Etienne Guettard (17-15-1786), French geologist. |
| Name Pronunciation: |
Guettardite + Pronunciation  |
| Synonym: |
IMA1966-018 |
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Guettardite Crystallography
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| Axial Ratios: |
a:b:c =2.5289:1:1.1028 |
| Cell Dimensions: |
a = 20.095, b = 7.946, c = 8.763, Z = 8; beta = 101.2° V = 1,372.58 Den(Calc)= 5.20 |
| Crystal System: |
Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 21/a |
| X Ray Diffraction: |
By Intensity(I/Io): 3.52(1), 2.795(0.9), 4.19(0.5), |
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Physical Properties of Guettardite
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| Cleavage: |
{001} Perfect |
| Color: |
Grayish black. |
| Density: |
5.31 |
| Diaphaneity: |
Opaque |
| Fracture: |
Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments. |
| Habit: |
Acicular - Occurs as needle-like crystals. |
| Habit: |
Anhedral Grains - Granular minerals without the expression of crystal shapes |
| Hardness: |
4 - Fluorite |
| Luster: |
Metallic |
| Streak: |
brownish |
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Optical Properties of Guettardite
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| RL Color: |
White with reddish internal reflections. |
| RL Pleochroism: |
Relatively strong. |
| Reflectivity |
Standardized Intensity (100%) Reflection Spectra of Guettardite in Air
| λ |
R1 |
R2 |
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∑ R1(λ) |
∑ R2(λ) |
| 470 nm |
37.60 |
42.60 |
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| 546 nm |
36.10 |
41.20 |
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| 589 nm |
34.80 |
39.30 |
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| 650 nm |
33.80 |
36.70 |
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Calculated Relative Intensity Colors of Guettardite in Air
Relative
Intensity |
0% |
30% |
60% |
90% |
100% |
120% |
150% |
180% |
210% |
240% |
260% |
| R1 |
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| R2 |
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Calculated Properties of Guettardite
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| Electron Density: |
Bulk Density (Electron Density)=4.49 gm/cc
note: Specific Gravity of Guettardite =5.20 gm/cc.
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| Fermion Index: |
Fermion Index = 0.08
Boson Index = 0.92 |
| Photoelectric: |
PEGuettardite = 781.87 barns/electron
U=PEGuettardite x rElectron Density=3,511.20 barns/cc.
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| Radioactivity: |
GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Guettardite is Not Radioactive |
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Guettardite Classification
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| Dana Class: |
03.07.08.02 (03)Sulfides - Sulfosalts |
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(03.07)where z/y = 2 - (A+)i (A++)j [By Cz], A=metals, B=semi-metals, C=non-metals |
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(03.07.08)Sartorite Group |
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03.07.08.01 Sartorite PbAs2S4 P 21/c 2/m |
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03.07.08.02 Guettardite Pb(Sb,As)2S4 P 21/a 2/m |
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03.07.08.03 Twinnite Pb(Sb,As)2S4 P1 1 |
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03.07.08.04 Marumoite! Pb32As40S92 P 21 2 |
| Strunz Class: |
02.HC.05a 02 - SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulf |
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02.H - Sulfosalts of SnS Archetype |
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02.HC -With only Pb |
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02.HC.05a Guettardite Pb(Sb,As)2S4 P 21/a 2/m |
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02.HC.05a Sartorite PbAs2S4 P 21/c 2/m |
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02.HC.05a Twinnite Pb(Sb,As)2S4 P1 1 |
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Other Guettardite Information
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| References: |
NAME( AntBidBlaNic1) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic1) |
| 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 :
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Guettardite
Pb(Sb,As)2S4
Dana No: 03.07.08.02 Strunz No: 02.HC.05a
Locality:
Notes:
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