|
|
Geffroyite Mineral Data
|
|
|
General Geffroyite Information
|
Chemical Formula: |
(Ag,Cu,Fe)9(Se,S)8 |
Composition: |
Molecular Weight = 1,342.22 gm |
|
Iron 3.74 % Fe |
|
Copper 12.78 % Cu |
|
Silver 43.40 % Ag |
|
Selenium 35.30 % Se |
|
Sulfur 4.78 % S |
|
______ |
|
100.00 % |
Empirical Formula: |
Ag5.4Cu2.7Fe2+0.9Se6S2 |
Environment: |
As late stage deposits in veins cutting granite. Micro-myrmikitic texture intergrowth with clausthalite and eskebornite. |
IMA Status: |
Approved IMA 1982 |
Locality: |
From Chameane, Puy-de-Dome, France. Link to MinDat.org Location Data. |
Name Origin: |
To honor Jaques Geffroy, metallugist for the French Atomic Energy Commission. |
Name Pronunciation: |
Geffroyite + Pronunciation |
|
Geffroyite Image |
Images:
|
|
Geffroyite
Comments: Silvery-gray grains of geffroyite to <0.5mm embedded in tan barite matrix.
Location: Moctezuma mine, Moctezuma, Sonora, Mexcio.
Scale: Overall: 3 x 2 x 2 cm.
© Tom Loomis / Dakota Matrix |
|
Geffroyite Crystallography
|
Cell Dimensions: |
a = 10.889, Z = 3; V = 1,291.11 Den(Calc)= 5.18 |
Crystal System: |
Isometric - Hexoctahedral H-M Symbol (4/m 3 2/m) Space Group: F m3m |
X Ray Diffraction: |
By Intensity(I/Io): 1.925(1), 3.145(0.9), 3.282(0.9), |
|
Physical Properties of Geffroyite
|
Color: |
Bronze brown. |
Density: |
5.39 |
Diaphaneity: |
Opaque |
Hardness: |
2.5 - Finger Nail |
Luster: |
Metallic |
|
Optical Properties of Geffroyite
|
RL Color: |
Brown with a creamy tint. |
Reflectivity |
Standardized Intensity (100%) Reflection Spectra of Geffroyite in Air
λ |
R |
|
∑ R(λ) |
420 nm |
19.00 |
|
|
440 nm |
21.40 |
|
460 nm |
23.50 |
|
480 nm |
25.50 |
|
500 nm |
27.50 |
|
520 nm |
29.10 |
|
540 nm |
30.10 |
|
560 nm |
31.70 |
|
580 nm |
32.70 |
|
600 nm |
33.60 |
|
620 nm |
34.40 |
|
640 nm |
35.10 |
|
660 nm |
35.80 |
|
680 nm |
36.30 |
|
700 nm |
36.90 |
|
Calculated Relative Intensity Colors of Geffroyite in Air
Relative Intensity |
0% |
40% |
80% |
100% |
120% |
160% |
200% |
240% |
280% |
320% |
360% |
390% |
R |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Calculated Properties of Geffroyite
|
Electron Density: |
Bulk Density (Electron Density)=4.57 gm/cc note: Specific Gravity of Geffroyite =5.18 gm/cc. |
Fermion Index: |
Fermion Index = 0.02 Boson Index = 0.98 |
Photoelectric: |
PEGeffroyite = 147.93 barns/electron U=PEGeffroyite x rElectron Density= 675.39 barns/cc. |
Radioactivity: |
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Geffroyite is Not Radioactive |
|
Geffroyite Classification
|
Dana Class: |
02.07.01.06 (02)Sulfides - Including Selenides and Tellurides |
|
(02.07)where Am Bn Xp, with (m+n):p=9:8 |
|
(02.07.01)Pentalndite Group (Isometric: Fm3m) |
|
02.07.01.01 Pentlandite (Fe,Ni)9S8 F m3m 4/m 3 2/m |
|
02.07.01.02 Argentopentlandite Ag(Fe,Ni)8S8 F m3m 4/m 3 2/m |
|
02.07.01.03 Cobaltpentlandite Co9S8 F m3m 4/m 3 2/m |
|
02.07.01.04 Shadlunite (Pb,Cd)(Fe,Cu)8S8 F m3m 4/m 3 2/m |
|
02.07.01.05 Manganoshadlunite (Mn,Pb)(Cu,Fe)8S8 F m3m 4/m 3 2/m |
|
02.07.01.06 Geffroyite (Ag,Cu,Fe)9(Se,S)8 F m3m 4/m 3 2/m |
Strunz Class: |
02.BB.15a 02 - SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulf |
|
02.B - Metal Sulfides, M:S > 1:1 (mainly 2:1) |
|
02.BB -With Ni, Fe |
|
02.BB.15a Argentopentlandite Ag(Fe,Ni)8S8 F m3m 4/m 3 2/m |
|
02.BB.15a Cobaltpentlandite Co9S8 F m3m 4/m 3 2/m |
|
02.BB.15a Geffroyite (Ag,Cu,Fe)9(Se,S)8 F m3m 4/m 3 2/m |
|
02.BB.15a Manganoshadlunite (Mn,Pb)(Cu,Fe)8S8 F m3m 4/m 3 2/m |
|
02.BB.15a Pentlandite (Fe,Ni)9S8 F m3m 4/m 3 2/m |
|
02.BB.15a Shadlunite (Pb,Cd)(Fe,Cu)8S8 F m3m 4/m 3 2/m |
|
Other Geffroyite Information
|
References: |
NAME( AntBidBlaNic1) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic1) |
See Also: |
Links to other databases for Geffroyite :
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
Search for Geffroyite using:
[AOL]
[Bing]
[Dog Pile]
[GeoScienceWorld]
[HotBot]
[Ixquick]
[Lycos]
[MAMMA]
[Scirus]
[Teoma]
[WebCrawler]
[Wikipedia]
[YAHOO]
Visit our Advertisers for Geffroyite :
Ask about Geffroyite 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
Espa�ol
Print or Cut-and-Paste your Geffroyite Specimen Label here :
Geffroyite
(Ag,Cu,Fe)9(Se,S)8
Dana No: 02.07.01.06 Strunz No: 02.BB.15a
Locality:
Notes:
|
|
|
|
|
|
Dakota Matrix
Excalibur Minerals
Exceptional Minerals
Hudson Insitute
John Betts Fine Minerals
Mc Dougall Minerals
Mineral News
Rock and Mineral Shows
Weinrich Minerals, Inc.