Vote for your favorite mineral in #MinCup26! - Sphalerite vs. Anorthite
Both zinc ore Sphalerite and calcium plagioclase feldspar Anorthite have perfect cleavage that will split cleanly if you hit them with a hammer, but only one can claim a larger split of your votes!
Log InRegister
Quick Links : The Mindat ManualThe Rock H. Currier Digital LibraryMindat Newsletter [Free Download]
Home PageAbout MindatThe Mindat ManualHistory of MindatCopyright StatusWho We AreContact UsAdvertise on Mindat
Donate to MindatCorporate SponsorshipSponsor a PageSponsored PagesMindat AdvertisersAdvertise on Mindat
Learning CenterWhat is a mineral?The most common minerals on earthInformation for EducatorsMindat ArticlesThe ElementsThe Rock H. Currier Digital LibraryGeologic TimeExplore Fossils
Minerals by PropertiesMinerals by ChemistryMineral Visual ExplorerAdvanced Locality SearchRandom MineralRandom LocalitySearch by minIDLocalities Near MeSearch ArticlesSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
Keyword(s):
 
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
Mining CompaniesStatisticsUsersMineral MuseumsClubs & OrganizationsMineral Shows & EventsThe Mindat DirectoryDevice SettingsThe Mineral QuizTime Machine
Photo SearchPhoto GalleriesSearch by ColorPhoto Colour ExplorerNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day GalleryPhotography

Geffroyite

A valid IMA mineral species
This page is currently not sponsored. Click here to sponsor this page.
01962590017271923329158.jpg
Geffroyite, etc.

Chaméane Uranium Deposit, Le Vernet-Chaméane, Issoire, Puy-de-Dôme, Auvergne-Rhône-Alpes, France
05933320017271923358422.jpg
Geffroyite

San Miguel Mine, Moctezuma, Moctezuma Municipality, Sonora, Mexico
01962590017271923329158.jpg
Geffroyite, etc.

Chaméane Uranium Deposit, Le Vernet-Chaméane, Issoire, Puy-de-Dôme, Auvergne-Rhône-Alpes, France
05933320017271923358422.jpg
Geffroyite

San Miguel Mine, Moctezuma, Moctezuma Municipality, Sonora, Mexico
01962590017271923329158.jpg
Geffroyite, etc.

Chaméane Uranium Deposit, Le Vernet-Chaméane, Issoire, Puy-de-Dôme, Auvergne-Rhône-Alpes, France
05933320017271923358422.jpg
Geffroyite

San Miguel Mine, Moctezuma, Moctezuma Municipality, Sonora, Mexico
Hide all sections | Show all sections

About GeffroyiteHide

00057000017271923418973.jpg
Jacques Geffroy
Formula:
(Cu,Fe,Ag)9(Se,S)8
Lustre:
Metallic
Hardness:
2½
Specific Gravity:
5.39 (Calculated)
Crystal System:
Isometric
Name:
Named in honor of Jacques Geffroy (1918–1993), French geologist and metallurgist at the French Atomic Energy Commission. He published many books and articles for the general public.
This page provides mineralogical data about Geffroyite.


Unique IdentifiersHide

Mindat ID:
1667
Long-form identifier:
mindat:1:1:1667:0

Similar NamesHide

JeffreyiteA valid IMA mineral species(Ca,Na)2(Be,Al)(Si2O7,HSi2O7)

IMA Classification of GeffroyiteHide

IMA status:
Approved
IMA Formula:
(Cu,Fe,Ag)9Se8
Approval year:
1980
First published:
1982

Classification of GeffroyiteHide

Strunz-mindat (2026):
2.BB.15

2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
B : Metal Sulfides, M: S > 1: 1 (mainly 2: 1)
B : With Ni
Dana 8th ed.:
2.7.1.6

2 : SULFIDES
7 : AmBnXp, with (m+n):p = 9:8
Hey's CIM Ref.:
3.2.18

3 : Sulphides, Selenides, Tellurides, Arsenides and Bismuthides (except the arsenides, antimonides and bismuthides of Cu, Ag and Au, which are included in Section 1)
2 : Sulphides etc. of Ag

Mineral SymbolsHide

As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.

SymbolSourceReference for Standard
GefIMA–CNMNCWarr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43

Physical Properties of GeffroyiteHide

Lustre:
Metallic
Transparency:
Opaque
Hardness:
2½ on Mohs scale
Hardness:
VHN15=67 - 72 kg/mm2 - Vickers
Density:
5.39 g/cm3 (Calculated)

Optical Data of GeffroyiteHide

Reflectivity:
WavelengthR1 (%)
420nm19.0%
440nm21.4%
460nm23.5%
480nm25.5%
500nm27.5%
520nm29.1%
540nm30.1%
560nm31.7%
580nm32.7%
600nm33.6%
620nm34.4%
640nm35.1%
660nm35.8%
680nm36.3%
700nm36.9%


Graph shows reflectance levels at different wavelengths (in nm). Peak reflectance is 36.9%.
Colour in reflected light:
Brown with creamy tint

Chemistry of GeffroyiteHide

Mindat Formula:
(Cu,Fe,Ag)9(Se,S)8
Element Weights:
Element% weight
Se52.483 %
Cu47.517 %

Calculated from ideal end-member formula.
Elements listed:
Ag, Cu, Fe, S, Se - search for minerals with similar chemistry

Crystallography of GeffroyiteHide

Crystal System:
Isometric
Class (H-M):
m3m(4/m32/m) - Hexoctahedral
Space Group:
Fm3m
Setting:
Fm3m
Cell Parameters:
a = 10.889 Å
Unit Cell V:
1,291.11 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Micro myrmekitic intergrowth with clausthalite and eskebornite.

X-Ray Powder DiffractionHide

Powder Diffraction Data:
d-spacingIntensity
1.925 Å(100)
3.282 Å(90)
3.145 Å(90)
2.094 Å(60)
1.112 Å(60)
1.660 Å(50)
2.436 Å(40)
Comments:
Chaméane mine, France. Data from the type description.

Geological EnvironmentHide

Paragenetic Mode(s):
Paragenetic ModeEarliest Age (Ga)
High-? alteration and/or metamorphism
33 : Minerals deposited by hydrothermal metal-rich fluids (see also [#12])

Type Occurrence of GeffroyiteHide

Type Locality:
ⓘ Chaméane Uranium Deposit, Le Vernet-Chaméane, Issoire, Puy-de-Dôme, Auvergne-Rhône-Alpes, France
General Appearance of Type Material:
Very fine-grained intergrowth (0.2-0.7 mm) with other selenides.
Place of Conservation of Type Material:
National School of Mines, Paris, France, number 54615 (holotype).
Geological Setting of Type Material:
Late stage veins cutting granite.
Associated Minerals at Type Locality:
BukoviteAthabascaiteUmangiteEucairiteEskebornite
ClausthaliteAnkeriteChalcopyriteChaméanite

Synonyms of GeffroyiteHide

Other Language Names for GeffroyiteHide

German:Geffroyit
Spanish:Geffroyita

Relationship of Geffroyite to other SpeciesHide

Member of:
Pentlandite Group > Pentlandite Supergroup
Other Members of Pentlandite Group:
ArgentopentlanditeAg(Fe,Ni)8S8Iso. m3m(4/m32/m) : Fm3m
CobaltpentlanditeCo9S8Iso. m3m(4/m32/m) : Fm3m
OberthüriteRh3Ni32S32Iso.
Pentlandite(NixFey)Σ9S8Iso. m3m(4/m32/m) : Fm3m
Shadlunite(Pb,Cd)(Fe,Cu)8S8Iso. m3m(4/m32/m) : Fm3m
SugakiiteCu(Fe,Ni)8S8Tet. 4/mmm(4/m2/m2/m) : P42/mnm
WangyanitePdNi8S8Iso. m3m(4/m32/m) : Fd3c

Common AssociatesHide

Associations Based on Photo Data:
3 photos of Geffroyite associated with EskeborniteCuFeSe2
3 photos of Geffroyite associated with UraniniteUO2
1 photo of Geffroyite associated with FischesseriteAg3AuSe2
1 photo of Geffroyite associated with CalciteCaCO3

Related Minerals - Strunz-mindat GroupingHide

2.BB.ArsenotučekiteNi18Sb3AsS16Tet. 4mm : I4mm
2.BB.HrabákiteNi9PbSbS8Tet. 4/mmm(4/m2/m2/m) : P4/mmm
2.BB.'UM2007-27-S:CuFeIrNiRh'(Ni,Fe,Cu,Rh,Ir)11S9
2.BB.HoromaniteFe6Ni3S8Tet. 4/mmm(4/m2/m2/m) : P4/mmm
2.BB.SamaniiteCu2Fe5Ni2S8Tet. 4/mmm(4/m2/m2/m) : P42/mnm
2.BB.05HeazlewooditeNi3S2Trig. 32 : R32
2.BB.05'UM2007-30-S:Fe'Fe3S2
2.BB.05Vozhminite(Ni,Co)4(As,Sb)S2Hex.
2.BB.05OregoniteNi2FeAs2Hex.
2.BB.10HauchecorniteNi9BiSbS8Tet. 4/mmm(4/m2/m2/m) : P4/mmm
2.BB.10ArsenohauchecorniteNi18Bi3AsS16Tet.
2.BB.10TellurohauchecorniteNi9Bi(Te,Bi)S8Tet. 4/mmm(4/m2/m2/m) : P4/mmm
2.BB.10JinxiuiteNi18Bi2SbAsS16Tet. 4/mmm(4/m2/m2/m) : I4/mmm
2.BB.10BismutohauchecorniteNi9Bi2S8Tet. 4/mmm(4/m2/m2/m) : P4/mmm
2.BB.10TučekiteNi9Sb2S8Tet. 4/mmm(4/m2/m2/m) : P4/mmm
2.BB.15ArgentopentlanditeAg(Fe,Ni)8S8Iso. m3m(4/m32/m) : Fm3m
2.BB.15Shadlunite(Pb,Cd)(Fe,Cu)8S8Iso. m3m(4/m32/m) : Fm3m
2.BB.15Ferhodsite(Fe,Rh,Ni,Ir,Cu,Pt)9S8Tet.
2.BB.15CobaltpentlanditeCo9S8Iso. m3m(4/m32/m) : Fm3m
2.BB.15'UM2002-26-S:FeNi'(Ni,Fe)9S8Hex.
2.BB.15Pentlandite(NixFey)Σ9S8Iso. m3m(4/m32/m) : Fm3m
2.BB.15OberthüriteRh3Ni32S32Iso.
2.BB.15Kharaelakhite(Cu,Pt,Pb,Fe,Ni)9S8Orth. mmm(2/m2/m2/m) : Pmmm
2.BB.15'Manganoshadlunite'(Mn,Pb,Cd)(Cu,Fe)8S8
2.BB.15SugakiiteCu(Fe,Ni)8S8Tet. 4/mmm(4/m2/m2/m) : P42/mnm
2.BB.15Godlevskite(Ni,Fe)9S8Orth. 222 : C222
2.BB.15WangyanitePdNi8S8Iso. m3m(4/m32/m) : Fd3c

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.

Internet Links for GeffroyiteHide

References for GeffroyiteHide

Localities for GeffroyiteHide

Showing 15 localities.

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.
Hide all sections | Show all sections

Locality ListHide

- 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). 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 (e.g. from pseudomorphs).

All localities listed without proper references should be considered as questionable.
Argentina
 
  • Córdoba Province
    • Calamuchita Department
      • Río de Los Sauces District
Mutti et al. (2005)
Australia
 
  • Tasmania
    • West Coast municipality
      • Queenstown district
        • Queenstown
Bottrill (2000)
Canada
 
  • Ontario
    • Greater Sudbury
      • Levack Township
Vale SA
Ames et al. (2003)
Chile
 
  • Antofagasta
    • Antofagasta Province
      • Antofagasta
Arfè et al. (2016)
Czech Republic
 
  • Plzeň Region
    • Tachov District
      • Zadní Chodov
Scharmová et al. (1995)
Egypt
 
  • Red Sea Governorate
El Monsef et al. (2018)
El Salvador
 
  • Usulután Department
    • Berlín
implications for metal transport in natural systems. Journal of volcanology and geothermal research (1) +1 other reference
France (TL)
 
  • Auvergne-Rhône-Alpes
    • Puy-de-Dôme
      • Issoire
        • Le Vernet-Chaméane
Johan et al. (1982) +1 other reference
Germany
 
  • Saxony-Anhalt
    • Mansfeld-Südharz
      • Mansfeld
Wittern (2001)
Mexico
 
  • Sonora
    • Moctezuma Municipality
Braith et al. (2001)
Mineralogical Society of America - ...
Portugal
 
  • Vila Real
    • Sabrosa
Gaspar et al. (1987)
USA
 
  • California
    • Inyo County
      • Inyo Mts (Inyo Range)
        • Malpais Mesa
Adams (2016) +1 other reference
  • Montana
    • Lewis and Clark County
      • Marysville Mining District
Gearity (2013)
Quick NavTopAbout GeffroyiteUnique IdentifiersSimilar NamesIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography X-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesRelationshipsCommon AssociatesStrunz-MindatOther InformationInternet Links References Localities Locality List
 
and/or  
Mindat.org® is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization. Mindat® and mindat.org® are registered trademarks of the Hudson Institute of Mineralogy.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2026, except where stated. Most political location boundaries are © OpenStreetMap contributors. Mindat.org relies on the contributions of thousands of members and supporters. Founded in 2000 by Jolyon Ralph and Ida Chau.
Content on this site may not be used to train, fine-tune, or otherwise develop artificial intelligence or machine learning models without prior written permission - see our Terms & Conditions.
To cite: Ralph, J., Von Bargen, D., Martynov, P., Zhang, J., Que, X., Prabhu, A., Morrison, S. M., Li, W., Chen, W., & Ma, X. (2025). Mindat.org: The open access mineralogy database to accelerate data-intensive geoscience research. American Mineralogist, 110(6), 833–844. doi:10.2138/am-2024-9486.
Privacy Policy - Terms & Conditions - Contact Us / DMCA issues - Report a bug/vulnerability Current server date and time: September 3, 2026 01:14:02 Page updated: August 19, 2026 02:35:33
Go to top of page