Laffittite
A valid IMA mineral species
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About Laffittite
Pierre Laffitte (1925 - )
Formula:
AgHgAsS3
Colour:
Dark red to cherry-red, may be very dark-red with only red glints
Lustre:
Adamantine, Metallic
Hardness:
3½
Specific Gravity:
6.11
Crystal System:
Monoclinic
Name:
Named in 1974 by Zdeněk Johan, Joseph Mantienne, and R. Picot in honor of Pierre Paul Laffitte (January 1, 1925 Saint-Paul-de-Vence, Alpes-Maritimes, France - ), director of BRGM (French Geological Survey), then director and president of Ecole Nationale Supérieure des Mines de Paris.
Unique Identifiers
Mindat ID:
2311
Long-form identifier:
mindat:1:1:2311:1
IMA Classification of Laffittite
Approved
IMA Formula:
Ag1+Hg2+As3+S2-3
Approval year:
1973
First published:
1974
Classification of Laffittite
2.GA.35
2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
G : Sulfarsenites, sulfantimonites, sulfbismuthites
A : Neso-sulfarsenites, etc. without additional S
2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
G : Sulfarsenites, sulfantimonites, sulfbismuthites
A : Neso-sulfarsenites, etc. without additional S
3.4.10.2
3 : SULFOSALTS
4 : ø = 3
3 : SULFOSALTS
4 : ø = 3
5.4.4
5 : Sulphosalts - Sulpharsenites and Sulphobismuthites (those containing Sn, Ge,or V are in Section 6)
4 : Sulpharsenites etc. of Zn and Hg
5 : Sulphosalts - Sulpharsenites and Sulphobismuthites (those containing Sn, Ge,or V are in Section 6)
4 : Sulpharsenites etc. of Zn and Hg
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Lft | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Laffittite
Adamantine, Metallic
Transparency:
Opaque
Colour:
Dark red to cherry-red, may be very dark-red with only red glints
Streak:
Pale cherry-red to brownish red
Hardness:
3½ on Mohs scale
Hardness:
VHN25=92 - 138 kg/mm2 - Vickers
Tenacity:
Brittle
Cleavage:
Distinct/Good
Good to imperfect on {010}
Good to imperfect on {010}
Fracture:
Conchoidal
Density:
6.11 g/cm3 (Measured) 6.195 g/cm3 (Calculated)
Comment:
Measured is on synthetic material
Optical Data of Laffittite
Anisotropism:
Strong to moderate, pale gray-blue to dark gray
Reflectivity:
| Wavelength | R1 (%) | R2 (%) |
|---|---|---|
| 400nm | 34.5% | 38.4% |
| 420nm | 34.6% | 37.7% |
| 440nm | 34.7% | 37.0% |
| 460nm | 34.4% | 36.1% |
| 480nm | 33.8% | 35.2% |
| 500nm | 32.9% | 34.3% |
| 520nm | 31.8% | 33.4% |
| 540nm | 30.7% | 32.5% |
| 560nm | 29.5% | 31.7% |
| 580nm | 28.6% | 30.8% |
| 600nm | 28.0% | 30.1% |
| 620nm | 27.4% | 29.7% |
| 640nm | 27.1% | 29.4% |
| 660nm | 26.8% | 29.4% |
| 680nm | 26.6% | 29.2% |
| 700nm | 26.3% | 28.9% |
Graph shows reflectance levels at different wavelengths (in nm). Peak reflectance is 38.4%.
R1 shown in black, R2 shown in red
Colour in reflected light:
Bluish white
Internal Reflections:
Purple-red
Pleochroism:
Strong
Chemistry of Laffittite
Mindat Formula:
AgHgAsS3
Element Weights:
Elements listed:
Crystallography of Laffittite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Cell Parameters:
a = 7.732(3) Å, b = 11.285(7) Å, c = 6.643(4) Å
β = 115.16(3)°
β = 115.16(3)°
Ratio:
a:b:c = 0.685 : 1 : 0.589
Unit Cell V:
524.65 ų (Calculated from Unit Cell)
Z:
4
Twinning:
{100}, twin axis ⊥ {100}; also by an unknown law giving intergrowths at a 60 degree angle
Comment:
Space Group: A2/a
Crystal Structure
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Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure
| ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
|---|---|---|---|---|---|---|---|
| 0017799 | Laffittite | Pervukhina N V, Borisov S V, Magarill S A, Vasil'ev V I, Kuratieva N V (2010) Redetermination and crystallographic analysis of the structure of Sb-containing laffittite AgHg(As,Sb)S3 from Chauvai (Kyrgyzstan) Journal of Structural Chemistry 51 683-688 | 2010 | Chauvai deposit, Kyrgyzstan | 0 | 293 | |
| 0000889 | Laffittite | Nakai I, Appleman D E (1983) Laffittite, AgHgAsS3: crystal structure and second occurrence from the Getchell mine, Nevada American Mineralogist 68 235-244 |  | 1983 | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 2.682 Å | (100) |
| 3.198 Å | (80) |
| 3.005 Å | (80) |
| 3.505 Å | (70) |
| 2.133 Å | (60) |
| 5.31 Å | (50) |
| 1.905 Å | (50) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| High-? alteration and/or metamorphism | |
| 33 : Minerals deposited by hydrothermal metal-rich fluids (see also [#12]) |
Type Occurrence of Laffittite
General Appearance of Type Material:
Grains up to 0.2 mm
Place of Conservation of Type Material:
National School of Mines, Paris, France.
Geological Setting of Type Material:
Dolomitic rocks
Associated Minerals at Type Locality:
Synonyms of Laffittite
Other Language Names for Laffittite
Common Associates
Associations Based on Photo Data:
| 21 photos of Laffittite associated with Orpiment | As2S3 |
| 11 photos of Laffittite associated with Realgar | As4S4 |
| 8 photos of Laffittite associated with Getchellite | AsSbS3 |
| 4 photos of Laffittite associated with Quartz | SiO2 |
| 3 photos of Laffittite associated with Stibnite | Sb2S3 |
| 2 photos of Laffittite associated with Calcite | CaCO3 |
| 2 photos of Laffittite associated with Routhierite | Tl(Cu,Ag)(Hg,Zn)2(As,Sb)2S6 |
| 1 photo of Laffittite associated with Cinnabar | HgS |
| 1 photo of Laffittite associated with Pierrotite | Tl2(Sb,As)10S16 |
Related Minerals - Strunz-mindat Grouping
| 2.GA. | Pyradoketosite | Ag3SbS3 |
| 2.GA. | Arsiccioite | AgHg2Tl(As,Sb)2S6 |
| 2.GA. | Eckerite | Ag2CuAsS3 |
| 2.GA.05 | Proustite | Ag3AsS3 |
| 2.GA.05 | Pyrargyrite | Ag3SbS3 |
| 2.GA.10 | Xanthoconite | Ag3AsS3 |
| 2.GA.10 | Pyrostilpnite | Ag3SbS3 |
| 2.GA.15 | Samsonite | Ag4MnSb2S6 |
| 2.GA.20 | Bytízite | Cu3SbSe3 |
| 2.GA.20 | Skinnerite | Cu3SbS3 |
| 2.GA.20 | Wittichenite | Cu3BiS3 |
| 2.GA.25 | Lapieite | NiCuSbS3 |
| 2.GA.25 | Lisiguangite | PtCuBiS3 |
| 2.GA.25 | Malyshevite | PdCuBiS3 |
| 2.GA.25 | Roterbärite | PdBiCuSe3 |
| 2.GA.25 | Mückeite | NiCu(Bi,Sb)S3 |
| 2.GA.30 | Aktashite | Cu6Hg3As4S12 |
| 2.GA.30 | Nowackiite | Cu6Zn3As4S12 |
| 2.GA.30 | Zhengminghuaite | Cu6Fe3As4S12 |
| 2.GA.30 | Gruzdevite | Cu6Hg3Sb4S12 |
| 2.GA.40 | 'Unnamed (Ag-Fe endmember of Routhierite Group)' | AgFe2TlAs2S6 |
| 2.GA.40 | Routhierite | Tl(Cu,Ag)(Hg,Zn)2(As,Sb)2S6 |
| 2.GA.40 | Stalderite | Tl(Cu,Ag)(Zn,Fe,Hg)2(As,Sb)2S6 |
| 2.GA.40 | Ralphcannonite | AgZn2TlAs2S6 |
| 2.GA.40 | Ferrostalderite | CuFe2TlAs2S6 |
| 2.GA.45 | Erniggliite | Tl2SnAs2S6 |
| 2.GA.50 | Cerromojonite | CuPbBiSe3 |
| 2.GA.50 | Seligmannite | PbCuAsS3 |
| 2.GA.50 | Součekite | CuPbBi(S,Se)3 |
| 2.GA.50 | 'Unnamed (Pb-Cu-Bi Selenide)' | PbCuBiSe3 |
| 2.GA.50 | Bournonite | PbCuSbS3 |
| 2.GA.55 | Eldragónite | Cu6BiSe4(Se2) |
Other Information
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Internet Links for Laffittite
mindat.org URL:
https://www.mindat.org/min-2311.html
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References for Laffittite
Reference List:
Johan, Zdenek, Mantienne, Joseph, Picot, Paul (1974) La routhiérite, TlHgAsS3, et la laffittite, AgHgAsS3, deux nouvelles espèces minérales. Bulletin de Minéralogie, 97 (1) 48-53 doi:10.3406/bulmi.1974.6914
Fleischer, Michael; Mandarino, Joseph A. (1975) New mineral names. American Mineralogist, 60 (9-10). 945-947
Nakai, Izumi, Appleman, Daniel E. (1983) Laffittite, AgHgAsS3: crystal structure and second occurrence from the Getchell mine, Nevada. American Mineralogist, 68 (1-2) 235-244
Borisov, S. V., Magarill, S. A., Pervukhina, N. V. (2009) Characteristic features of crystal chemistry of natural mercury-containing sulfides and sulfosalts. Journal of Structural Chemistry, 50 (5). 853-860 doi:10.1007/s10947-009-0127-7
Pervukhina, N. V., Borisov, S. V., Magarill, S. A., Vasil’ev, V. I., Kuratieva, N. V. (2010) Redetermination and Crystallographic Analysis of the Structure of Sb-Containing Laffittite AgHg(As,Sb)S3 From Chauvai (Kyrgyzstan). Journal of Structural Chemistry, 51 (4). 683-688 doi:10.1007/s10947-010-0100-5
Localities for Laffittite
Showing 9 localities.
symbol to view information about a locality.
The Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for references and further information on this occurrence.
? - Indicates mineral may be doubtful at this locality.
- Good crystals or important locality for species.
- World class for species or very significant.
(TL) - Type Locality for a valid mineral species.
(FRL) - First Recorded Locality for everything else (eg varieties).
All localities listed without proper references should be considered as questionable.
France (TL) | |
| Johan et al. (1974) +1 other reference |
Italy | |
| Biagioni et al. (2014) |
Kyrgyzstan | |
| Kolesar et al. (1993) +2 other references |
Russia | |
| Vikentyev et al. (2019) +3 other references |
USA | |
| Nakai et al. (1983) +1 other reference |
| - (2005) | |
| - (2005) | |
| Barrick Gold Corporation | |
| - (2005) |
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Jas Roux, La Chapelle-en-Valgaudemar, Gap, Hautes-Alpes, Provence-Alpes-Côte d'Azur, France