Laforetite Mineral Data

Laforetite Mineral Data

[Localities] [Carat Weight] [Special Collections] [Diamond Lots] [Ordering Info]
See Also: [Excalibur Minerals] [Mineral News] [Hudson Institute] [Minerals on CDROM]
Special Collections of Rough Diamonds for Researchers and Collectors
Unparalled diversity of specimens from different locations

General Laforetite Information

Chemical Formula:

AgInS2

Composition:

Molecular Weight = 286.82 gm

Indium 40.03 % In

Silver 37.61 % Ag

Sulfur 22.36 % S

______

100.00 %

Empirical Formula:

AgInS₂

Environment:

Breccia vein sample from the mine dumps. Microscopic inclusions in galena.

IMA Status:

Approved IMA 1995 (Dana # Added)

Locality:

The disused Montgros mine (Pinols claim), near the hamlet La Boriette, about 10 km SW of Langeac, Haute-Loire, France. Link to MinDat.org Location Data.

Name Origin:

Named for Claude P. Laforet (1936-) a metallographer at the Bureau de Recherches Geologiques et Minieres, who first observed the mineral from the Montgros mine.

Synonym:

IMA1995-006

Search for Laforetite Images

Images:

Image not yet available on Webmineral.com

Try searching images.google.com or Mindat Picture Gallary for mineral pictures. Caution: The images retrieved may not be appropriate.

Laforetite Crystallography

Axial Ratios:

a:c = 1:1.90646

Cell Dimensions:

a = 5.88, c = 11.21, Z = 4; V = 387.58 Den(Calc)= 4.92

Crystal System:

Tetragonal - ScalenohedralH-M Symbol (4 2m) Space Group: I 42d

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 3.351(1), 2.942(0.8), 1.768(0.8),2.03(0.75), 2.082(0.75), 1.189(0.4), 1.707(0.35),

Physical Properties of Laforetite

Cleavage:

None

Color:

Brown.

Diaphaniety:

Opaque

Habit:

Inclusions - Generally found as inclusions in other minerals.

Habit:

Microscopic Crystals - Crystals visible only with microscopes.

Hardness:

3 - Calcite

Luster:

Metallic

Streak:

chocolate brown

Optical Properties of Laforetite

RL Anisotrophism:

Strong, brick-red with an orange tint to bluish-gray purplish.

RL Color:

Brownish gray in oil with abundant strawberry red internal reflections.

RL Pleochroism:

Weak, from brown to brown-gray.

Reflectivity

**Standardized Intensity (100%) Reflection Spectra of Laforetite in Air**
λ	R	∑ R(λ)
480 nm	26.00
540 nm	24.60
580 nm	24.20
640 nm	24.60

**Calculated Relative Intensity Colors of Laforetite in Air**
Relative Intensity	0%	40%	80%	100%	120%	160%	200%	240%	280%	320%	360%
R

Calculated Properties of Laforetite

Electron Density:

r_electron=4.39 gm/cc
note: r_Laforetite=4.92 gm/cc.

Fermion Index

Fermion Index = 0.00167
Boson Index = 0.99833

Photoelectric:

PE_Laforetite= 213.69 barns/electron
U=PE_Laforetite x r_electron= 938.38 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)

Laforetite is Not Radioactive

Laforetite Classification

Dana Class:

2.9.1.6 (2)Sulfides - Including Selenides and Tellurides

(2.9)where Am Bn Xp, with (m+n):p=1:1

(2.9.1)Chalcopyrite Group (Tetragonal: I4¯2d)

2.9.1.1 Chalcopyrite CuFeS2 I 42d 4 2m

2.9.1.2 Eskebornite CuFeSe2 I 42d 4 2m

2.9.1.3 Gallite CuGaS2 I 42d 4 2m

2.9.1.4 Roquesite CuInS2 I 42d 4 2m

2.9.1.5 Lenaite AgFeS2 I 42d 4 2m

2.9.1.6 Laforetite ! AgInS2 I 42d 4 2m

Strunz Class:

II/C.03-50 II - Sulfides and sulphosalts

II/C - Sulfides with metal: sulfur, selenium and tellurium = 1:1

II/C.03 - Chalcopyrite group and related compounds

II/C.03-10 Chalcopyrite CuFeS2 I 42d 4 2m

II/C.03-20 Eskebornite CuFeSe2 I 42d 4 2m

II/C.03-25 Lenaite AgFeS2 I 42d 4 2m

II/C.03-30 Gallite CuGaS2 I 42d 4 2m

II/C.03-40 Roquesite CuInS2 I 42d 4 2m

II/C.03-50 Laforetite AgInS2 I 42d 4 2m

Other Laforetite Information

References:

NAME( MinRec, Vol 31, No 4) PHYS. PROP.(MinRec, Vol 31, No 4) OPTIC PROP.(AmMin, v 85, p 875)

See Also:

Links to other databases for Laforetite :
1 -Am. Min. Crystal Structure Database 2 -Athena 3 -Google Images 4 -Google Scholar 5 -Handbook of Mineralogy (UofA) 6 -MinDAT 7 -MinMax(Deutsch) 8 -MinMax(English) 9 -Mineralienatlas (Deutsch) 10 -QUT Mineral Atlas

Search for Laforetite using:

[ALTAVISTA] [AOL] [About.com] [All-The-Web] [HotBot] [Ixquick] [LookSmart] [MAMMA] [MSN.COM] [Netscape] [Teoma] [Wikipedia] [YAHOO]

Visit our Advertisers for Laforetite :
AA Mineral Specimens
B and L Minerals
Dan Weinrich Fine Minerals
Dan Weinrich Auctions
e-Rocks Auctions
Excalibur Minerals
Exceptional Minerals
Fabre Minerals
Greenside Minerals
John Betts Fine Minerals
Masons Minerals
Minernet.it
Mineral News
Mineral of the Month Club
MineralsWeb Fine Minerals
Rockshop.cz Kalat Fine Minerals
T G Fine Minerals
Wrights Rock Shop

Translate Laforetite Mineral Data :

Ask about Laforetite here :
Ask-A-Mineralogist from the Mineralogical Society of America
Mindat.org's Discussion Groups
Original Rockhounds Discussion Group
Rockhounds Discussion Group on Yahoo Groups
Mineral Discussion Forum from Fabre Minerals - also available in Español

Print or Cut-and-Paste your Laforetite Specimen Label here :

Laforetite

AgInS2
Dana No: 2.9.1.6 Strunz No: II/C.03-50
Locality:

Notes: