Named for Claude P. Laforêt (b. 1936), metallographer at the Bureau de Recherches Géologiques et Minières, who first observed the mineral at the Montgros Mine.

Type Locality:

ⓘ Montgros Mine, Pinols, Pinols, Haute-Loire, Auvergne-Rhône-Alpes, France

Chalcopyrite Group.

Classification of LaforêtiteHide

IMA status:

Approved

Approval Year:

1995

Strunz 8th ed.:

2/C.03-45

Nickel-Strunz 10th (pending) ed.:

2.CB.10a

2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
C : Metal Sulfides, M: S = 1: 1 (and similar)
B : With Zn, Fe, Cu, Ag, etc.

Physical Properties of LaforêtiteHide

Lustre:

Metallic

Transparency:

Opaque

Colour:

Brown

Streak:

Chocolate brown

Hardness:

3 on Mohs scale

Hardness:

VHN₁₀₀=183 kg/mm² - Vickers

Hardness Data:

Estimated

Cleavage:

None Observed

Density:

4.93(1) g/cm³ (Calculated)

Optical Data of LaforêtiteHide

Type:

Anisotropic

Anisotropism:

Strong, brick red with orange tint to bluish-grey purplish

Reflectivity:

480nm	R=26%
540nm	R=24.6%
580nm	R=24.2%
660nm	R=25.8%

Graph shows reflectance levels at different wavelengths (in nm). Top of box is 100%. Peak reflectance is 26%.

Colour in reflected light:

Brownish grey

Internal Reflections:

strawberry red

Pleochroism:

Weak

Comments:

Brown to clear brown-grey tints

Chemical Properties of LaforêtiteHide

Formula:

AgInS₂

Elements listed:

Ag, In, S - search for minerals with similar chemistry

Common Impurities:

Cu,Fe,Se

Crystallography of LaforêtiteHide

Crystal System:

Tetragonal

Class (H-M):

4 2m - Scalenohedral

Space Group:

I4 2d

Cell Parameters:

a = 5.880(2) Å, c = 11.21(1) Å

Ratio:

a:c = 1 : 1.906

Unit Cell V:

387.57 Å³

Twinning:

Polysynthetic lamellar observed in polished sections.

X-Ray Powder DiffractionHide

Powder Diffraction Data:

d-spacing	Intensity
3.351	(100)
2.942	(80)
2.082	(75)
2.035	(75)
1.768	(80)
1.707	(35)
1.189	(40)

Comments:

From synthetic material because of small size of grains.

Type Occurrence of LaforêtiteHide

Type Locality:

ⓘ Montgros Mine, Pinols, Pinols, Haute-Loire, Auvergne-Rhône-Alpes, France

General Appearance of Type Material:

tiny < 30 μm anhedral inclusions in galena

Place of Conservation of Type Material:

Geological Museum of Lausanne, Switzerland (no. MGL 58600) and fragments of holotype material, with submicroscopic lafortite inclusions, are also deposited at the Galerie de Mineralogie, Museum National d'Histoire Naturelle, Paris, France.

Geological Setting of Type Material:

brecciated vein sample from the mine dump

Associated Minerals at Type Locality:

Synonyms of LaforêtiteHide

IMA1995-006

Other Language Names for LaforêtiteHide

German:Laforêtit

Russian:Лафоретит

Spanish:Laforêtita

Relationship of Laforêtite to other SpeciesHide

Member of:

Chalcopyrite Group

Other Members of this group:

Chalcopyrite	CuFeS₂	Tet. 4 2m : I4 2d
Eskebornite	CuFeSe₂	Tet.
Gallite	CuGaS₂	Tet. 4 2m : I4 2d
Lenaite	AgFeS₂	Tet. 4 2m : I4 2d
Roquesite	CuInS₂	Tet. 4 2m : I4 2d
Shenzhuangite	NiFeS₂	Tet. 4 2m : I4 2d
Unnamed (Cu-Mn-Sn Sulfide)	Cu₂MnSnS₄

Related Minerals - Nickel-Strunz Grouping Hide

2.CB.	Agmantinite	Ag₂MnSnS₄	Orth.
2.CB.05a	Coloradoite	HgTe	Iso. m3m (4/m 3 2/m)
2.CB.05a	Hawleyite	CdS	Iso. 4 3m : F4 3m
2.CB.05a	Metacinnabar	HgS	Iso. 4 3m : F4 3m
2.CB.05c	Polhemusite	(Zn,Hg)S	Tet.
2.CB.05b	Sakuraiite	(Cu,Zn,Fe)₃(In,Sn)S₄	Iso.
2.CB.05a	Sphalerite	ZnS	Iso. 4 3m : F4 3m
2.CB.05a	Stilleite	ZnSe
2.CB.05a	Tiemannite	HgSe	Iso. 4 3m : F4 3m
2.CB.05	UM1998-15-S:CuFeZn	Cu₂Fe₃Zn₅S₁₀
2.CB.05a	Rudashevskyite	(Fe,Zn)S	Iso. 4 3m : F4 3m
2.CB.10a	Chalcopyrite	CuFeS₂	Tet. 4 2m : I4 2d
2.CB.10a	Eskebornite	CuFeSe₂	Tet.
2.CB.10a	Gallite	CuGaS₂	Tet. 4 2m : I4 2d
2.CB.10b	Haycockite	Cu₄Fe₅S₈	Orth. 2 2 2
2.CB.10a	Lenaite	AgFeS₂	Tet. 4 2m : I4 2d
2.CB.10b	Mooihoekite	Cu₉Fe₉S₁₆	Tet.
2.CB.10b	Putoranite	Cu_1.1Fe_1.2S₂	Iso.
2.CB.10a	Roquesite	CuInS₂	Tet. 4 2m : I4 2d
2.CB.10b	Talnakhite	Cu₉(Fe,Ni)₈S₁₆	Iso. 4 3m : I4 3m
2.CB.15a	Černýite	Cu₂(Cd,Zn,Fe)SnS₄	Tet. 4 2m : I4 2m
2.CB.15a	Ferrokësterite	Cu₂(Fe,Zn)SnS₄	Tet. 4 : I4
2.CB.15a	Hocartite	Ag₂(Fe²⁺,Zn)SnS₄	Tet. 4 2m : I4 2m
2.CB.15a	Idaite	Cu₅FeS₆	Hex.
2.CB.15a	Kësterite	Cu₂ZnSnS₄	Tet. 4 : I4
2.CB.15a	Kuramite	Cu₃SnS₄	Tet.
2.CB.15b	Mohite	Cu₂SnS₃	Mon.
2.CB.15a	Pirquitasite	Ag₂ZnSnS₄	Tet. 4 : I4
2.CB.15a	Stannite	Cu₂FeSnS₄	Tet. 4 2m : I4 2m
2.CB.15c	Stannoidite	Cu⁺₆Cu²⁺₂(Fe²⁺,Zn)₃Sn₂S₁₂	Orth.
2.CB.15a	Velikite	Cu₂HgSnS₄	Tet.
2.CB.15c	UM2006-11-S:CuFeGeZn	Cu₈(Fe,Zn)₃Ge₂S₁₂ (?)
2.CB.20	Chatkalite	Cu₆FeSn₂S₈	Tet. 4 2m : P4m2
2.CB.20	Mawsonite	Cu₆Fe₂SnS₈	Tet. 4 2m : P4m2
2.CB.30	Colusite	Cu₁₃VAs₃S₁₆	Iso. 4 3m : P4 3n
2.CB.30	Germanite	Cu₁₃Fe₂Ge₂S₁₆	Iso. 4 3m : P4 3n
2.CB.30	Germanocolusite	Cu₂₆V₂(Ge,As)₆S₃₂	Iso.
2.CB.30	Nekrasovite	Cu₂₆V₂(Sn,As,Sb)₆S₃₂	Iso.
2.CB.30	Stibiocolusite	Cu₁₃V(Sb,Sn,As)₃S₁₆	Iso.
2.CB.30	Ovamboite	Cu₂₀(Fe,Cu,Zn)₆W₂Ge₆S₃₂	Iso.
2.CB.30	Maikainite	Cu₂₀(Fe,Cu)₆Mo₂Ge₆S₃₂
2.CB.35a	Hemusite	Cu₆SnMoS₈	Iso.
2.CB.35a	Kiddcreekite	Cu₆SnWS₈	Iso. 4 3m : F4 3m
2.CB.35a	Polkovicite	(Fe,Pb)₃(Ge,Fe)_1-xS₄	Iso.
2.CB.35a	Renierite	(Cu¹⁺,Zn)₁₁Fe₄(Ge⁴⁺,As⁵⁺)₂S₁₆	Tet. 4 2m : P4 2c
2.CB.35a	Vinciennite	Cu⁺₇Cu²⁺₃Fe²⁺₂Fe³⁺₂Sn(As,Sb)S₁₆	Tet.
2.CB.35a	Morozeviczite	(Pb,Fe)₃Ge_1-xS₄	Iso.
2.CB.35b	Catamarcaite	Cu₆GeWS₈	Hex. 6mm : P6₃mc
2.CB.40	Lautite	CuAsS	Orth. mmm (2/m 2/m 2/m) : Pnma
2.CB.45	Cadmoselite	CdSe	Hex. 6mm : P6₃mc
2.CB.45	Greenockite	CdS	Hex. 6mm : P6₃mc
2.CB.45	Wurtzite	(Zn,Fe)S	Hex. 6mm : P6₃mc
2.CB.45	Rambergite	MnS	Hex. 6mm : P6₃mc
2.CB.45	Buseckite	(Fe,Zn,Mn)S	Hex. 6mm : P6₃mc
2.CB.55a	Cubanite	CuFe₂S₃	Orth. mmm (2/m 2/m 2/m)
2.CB.55b	Isocubanite	CuFe₂S₃	Iso. m3m (4/m 3 2/m) : Fm3m
2.CB.60	Picotpaulite	TlFe₂S₃	Orth. mmm (2/m 2/m 2/m) : Cmcm
2.CB.60	Raguinite	TlFeS₂	Orth.
2.CB.65	Argentopyrite	AgFe₂S₃	Mon. 2/m
2.CB.65	Sternbergite	AgFe₂S₃	Orth. mmm (2/m 2/m 2/m)
2.CB.70	Sulvanite	Cu₃VS₄	Iso.
2.CB.75	Vulcanite	CuTe	Orth.
2.CB.80	Empressite	AgTe	Orth. mmm (2/m 2/m 2/m)
2.CB.85	Muthmannite	AuAgTe₂	Mon. 2/m : P2/m

Other InformationHide

Health Risks:

No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

References for LaforêtiteHide

Reference List:

Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)

Meisser, N., Thelin, P., Chiappero, P.J., Maurel, C. (1999) Laforêtite, AgInS2, a new mineral of the chalcopyrite group from the Montgros mine, Haute-Loire, France. European Journal of Mineralogy: 11: 891-897.

Jambor, J.L., Kovalenker, V.A., Roberts, A.C. (2000) New mineral names. American Mineralogist: 85: 873-877.

Mandarino, J.A. (2000) Abstracts of new mineral descriptions. Mineralogical Record: 31(4): 363-372.

Internet Links for LaforêtiteHide

mindat.org URL:

https://www.mindat.org/min-7149.html
Please feel free to link to this page.

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External Links:

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Raman and XRD data at RRUFF project

References and PDF downloads at RRUFF project

American Mineralogist Crystal Structure Database

Handbook of Mineralogy page PDF

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Localities for LaforêtiteHide

This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the

symbol to view information about a locality. The

symbol next to localities in the list can be used to jump to that position on the map.

Locality ListHide

- This locality has map coordinates listed.

- This locality has estimated coordinates. ⓘ - Click for 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). ~~Struck out~~ - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (eg from pseudomorphs.)

All localities listed without proper references should be considered as questionable.


France (TL)
Auvergne-Rhône-Alpes Haute-Loire Pinols Pinols ⓘ Montgros Mine (TL)	Meisser N. et al (1999) European Journal of Mineralogy 11: 891-897.

Japan
Hokkaidō Sapporo Minami-ku ⓘ Toyoha mine	Ishihara, S., & Matsueda, H. (2011). Chemical characteristics of the indium-polymetallic ores from the Toyoha mine, Hokkaido, Japan. Bulletin of the Geological Survey of Japan, 62(3/4), 131-142.

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Laforêtite

About LaforêtiteHide