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Laffittite Mineral Data
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General Laffittite Information
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 Chemical Formula: |
AgHgAsS3 |
| Composition: |
Molecular Weight = 479.58 gm |
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Silver 22.49 % Ag |
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Mercury 41.83 % Hg |
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Arsenic 15.62 % As |
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Sulfur 20.06 % S |
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______ |
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100.00 % |
| Empirical Formula: |
AgHgAsS3 |
| Environment: |
In a hydrothermal deposit with other arsenic sulfides. |
| IMA Status: |
Approved IMA 1974 |
| Locality: |
Jas Roux, Valgaudemar, Hautes-Alpes, Provence-Alpes-C�te d'Azur, France. Link to MinDat.org Location Data. |
| Name Origin: |
Named for Pierre Laffitte, Director, National School of Mines, Paris, France. |
| Name Pronunciation: |
Laffittite + Pronunciation  |
| Synonym: |
ICSD 31194 |
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PDF 35-436 |
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Laffittite Image |
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Images:
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Laffittite
Comments: A short-prismatic, dark brown crystal of laffittite with red realgar and yellow orpiment.
Location: Getchell Mine, Adam Peak, Humboldt Co., Nevada, USA.
Scale: Picture size 1.5 mm.
© Thomas Witzke / Abraxas-Verlag |
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Laffittite Crystallography
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| Axial Ratios: |
a:b:c =0.6851:1:0.5886 |
| Cell Dimensions: |
a = 7.732, b = 11.285, c = 6.643, Z = 4; beta = 115.16° V = 524.65 Den(Calc)= 6.07 |
| Crystal System: |
Monoclinic - Domatic H-M Symbol (m) Space Group: Aa |
| X Ray Diffraction: |
By Intensity(I/Io): 3.512(1), 3.202(0.78), 3.015(0.69), |
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Physical Properties of Laffittite
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| Cleavage: |
{???} Indistinct |
| Color: |
Dark red. |
| Density: |
6.07 |
| Diaphaneity: |
Translucent to Opaque |
| Hardness: |
3.5 - Copper Penny |
| Luster: |
Metallic |
| Streak: |
brownish red |
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Optical Properties of Laffittite
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| RL Anisotrophism: |
Strong, from light gray-blue to dark gray. |
| RL Color: |
Bluish white with numerous purple-red internal reflections. |
| RL Pleochroism: |
Strong. |
| Reflectivity |
Standardized Intensity (100%) Reflection Spectra of Laffittite in Air
| λ |
R1 |
R2 |
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∑ R1(λ) |
∑ R2(λ) |
| 400 nm |
34.50 |
38.40 |
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| 420 nm |
34.60 |
37.70 |
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| 440 nm |
34.70 |
37.00 |
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| 460 nm |
34.40 |
36.10 |
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| 480 nm |
33.80 |
35.20 |
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| 500 nm |
32.90 |
34.30 |
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| 520 nm |
31.80 |
33.40 |
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| 540 nm |
30.70 |
32.50 |
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| 560 nm |
29.50 |
31.70 |
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| 580 nm |
28.60 |
30.80 |
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| 600 nm |
28.00 |
30.10 |
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| 620 nm |
27.40 |
29.70 |
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| 640 nm |
27.10 |
29.40 |
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| 660 nm |
26.80 |
29.40 |
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| 680 nm |
26.60 |
29.20 |
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| 700 nm |
26.30 |
28.90 |
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Calculated Relative Intensity Colors of Laffittite in Air
Relative
Intensity |
0% |
40% |
80% |
100% |
120% |
160% |
200% |
240% |
280% |
310% |
| R1 |
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| R2 |
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Calculated Properties of Laffittite
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| Electron Density: |
Bulk Density (Electron Density)=5.27 gm/cc
note: Specific Gravity of Laffittite =6.07 gm/cc.
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| Fermion Index: |
Fermion Index = 0.12
Boson Index = 0.88 |
| Photoelectric: |
PELaffittite = 754.44 barns/electron
U=PELaffittite x rElectron Density=3,972.33 barns/cc.
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| Radioactivity: |
GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Laffittite is Not Radioactive |
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Laffittite Classification
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| Dana Class: |
03.04.10.02 (03)Sulfides - Sulfosalts |
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(03.04)where z/y > 3 - (A+)i (A++)j [By Cz], A=metals, B=semi-metals, C=non-metals |
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(03.04.10)Dana Group |
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03.04.10.01 Christite TlHgAsS3 P 21/n 2/m |
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03.04.10.02 Laffittite AgHgAsS3 Aa m |
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03.04.10.03 IMA2007-010! PbHgAs2S6 P lattice Mono |
| Strunz Class: |
02.GA.35 02 - SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulf |
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02.G - Sulfarsenites, sulfantimonites, sulfbismuthites |
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02.GA -Neso-sulfarsenites, etc., without additional S |
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02.GA.35 Laffittite AgHgAsS3 Aa m |
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Other Laffittite 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 Laffittite :
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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Laffittite
AgHgAsS3
Dana No: 03.04.10.02 Strunz No: 02.GA.35
Locality:
Notes:
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