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Eucairite

A valid IMA mineral species - grandfathered
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02224870017271922677545.jpg
Eucairite, etc.

Pƙedboƙice deposit, Pƙedboƙice, Kováƙov, Písek District, South Bohemian Region, Czech Republic
09176730017271922696658.jpg
Eucairite

Pƙedboƙice deposit, Pƙedboƙice, Kováƙov, Písek District, South Bohemian Region, Czech Republic
04263900017271922759254.jpg
Eucairite, etc.

Skrikerum Mine, Valdemarsvik, Östergötland County, Sweden
02224870017271922677545.jpg
Eucairite, etc.

Pƙedboƙice deposit, Pƙedboƙice, Kováƙov, Písek District, South Bohemian Region, Czech Republic
09176730017271922696658.jpg
Eucairite

Pƙedboƙice deposit, Pƙedboƙice, Kováƙov, Písek District, South Bohemian Region, Czech Republic
04263900017271922759254.jpg
Eucairite, etc.

Skrikerum Mine, Valdemarsvik, Östergötland County, Sweden
02224870017271922677545.jpg
Eucairite, etc.

Pƙedboƙice deposit, Pƙedboƙice, Kováƙov, Písek District, South Bohemian Region, Czech Republic
09105040017271922762188.jpg
Eucairite

Pƙedboƙice deposit, Pƙedboƙice, Kováƙov, Písek District, South Bohemian Region, Czech Republic
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About EucairiteHide

Formula:
AgCuSe
Colour:
Brilliant creamy white
Lustre:
Metallic
Hardness:
2½
Specific Gravity:
7.6 - 7.8
Crystal System:
Orthorhombic
Name:
For the Greek for opportunity, since it was first found shortly after the description of selenium.
This page provides mineralogical data about Eucairite.


Unique IdentifiersHide

Mindat ID:
1415
Long-form identifier:
mindat:1:1:1415:7

IMA Classification of EucairiteHide

Classification of EucairiteHide

Strunz-mindat (2025):
2.BA.50

2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
B : Metal Sulfides, M: S > 1: 1 (mainly 2: 1)
A : With Cu, Ag, Au
Dana 8th ed.:
2.4.6.2

2 : SULFIDES
4 : AmBnXp, with (m+n):p = 2:1
Hey's CIM Ref.:
3.2.13

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.

Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.

SymbolSourceReference
EcaIMA–CNMNCWarr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43
EucThe Canadian Mineralogist (2019)The Canadian Mineralogist (2019) The Canadian Mineralogist list of symbols for rock- and ore-forming minerals (December 30, 2019). download

Physical Properties of EucairiteHide

Lustre:
Metallic
Transparency:
Opaque
Colour:
Brilliant creamy white
Comment:
Tarnishes to bright orange
Streak:
Shining
Hardness:
2½ on Mohs scale
Hardness:
VHN25=27 - 31 kg/mm2 - Vickers
Tenacity:
Brittle
Fracture:
Irregular/Uneven, Conchoidal
Comment:
Somewhat sectile
Density:
7.6 - 7.8 g/cm3 (Measured)    7.91 g/cm3 (Calculated)

Optical Data of EucairiteHide

Anisotropism:
Strong olive-brown to steel-blue with a purplish tinge
Colour in reflected light:
Tin-white with faint creamy tinge
Pleochroism:
Weak

Chemistry of EucairiteHide

Mindat Formula:
AgCuSe
Element Weights:
Element% weight
Ag43.083 %
Se31.537 %
Cu25.380 %

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

Crystallography of EucairiteHide

Crystal System:
Orthorhombic
Cell Parameters:
a = 4.105 Å, b = 4.07 Å, c = 6.31 Å
Ratio:
a:b:c = 1.009 : 1 : 1.55
Unit Cell V:
105.42 ų (Calculated from Unit Cell)
Z:
10
Morphology:
Granular masses and blebs
Comment:
Orthorhombic, pseudotetragonal. Point Group: 4/m 2/m 2/m ;Space Group: P4/nmm.

Crystal StructureHide

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IDSpeciesReferenceLinkYearLocalityPressure (GPa)Temp (K)
0010578EucairiteFrueh A J, Czamanske G K, Knight C (1957) The crystallography of eucairite, CuAgSe Zeitschrift fur Kristallographie 108 389-3961957Skrikerum, Sweden0293
0010579EucairiteFrueh A J, Czamanske G K, Knight C (1957) The crystallography of eucairite, CuAgSe Zeitschrift fur Kristallographie 108 389-3961957Skrikerum, Sweden0293
CIF Raw Data - click here to close

X-Ray Powder DiffractionHide

Powder Diffraction Data:
d-spacingIntensity
2.12 Å(10)
2.61 Å(7)
2.88 Å(5)
2.48 Å(4)
2.02 Å(2)
3.14 Å(1)
1.861 Å(1)

Geological EnvironmentHide

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

Type Occurrence of EucairiteHide

Synonyms of EucairiteHide

Other Language Names for EucairiteHide

Common AssociatesHide

Associated Minerals Based on Photo Data:
73 photos of Eucairite associated with ClausthalitePbSe
60 photos of Eucairite associated with CalciteCaCO3
53 photos of Eucairite associated with KlockmanniteCuSe
46 photos of Eucairite associated with UmangiteCu3Se2
42 photos of Eucairite associated with BerzelianiteCu2-xSe (x ≈ 0.12)
29 photos of Eucairite associated with Thucholite
20 photos of Eucairite associated with CrookesiteCu7(Tl, Ag)Se4
19 photos of Eucairite associated with NaumanniteAg2Se
12 photos of Eucairite associated with TiemanniteHgSe
9 photos of Eucairite associated with UraniniteUO2

Related Minerals - Strunz-mindat GroupingHide

2.BA.MakotoiteAg12(Cu3Au)S8Trig. 3m (3 2/m) : R3c
2.BA.AlburniteAg8GeTe2S4Iso.
2.BA.DzierĆŒanowskiteCaCu2S2Trig. 3m (3 2/m) : P3m1
2.BA.XuwenyuaniteAg9Fe3+Te2S4Iso. 4 3m : F4 3m
2.BA.Orileyite(Fe,Cu)2As
2.BA.Juxingite Bi6Cu140Fe30S125Iso. 4 3m : F4 3m
2.BA.05DjurleiteCu31S16Mon. 2/m
2.BA.05GeeriteCu8S5Trig. 3
2.BA.05RoxbyiteCu58S32Tric. 1 : P1
2.BA.05ChalcociteCu2SMon. 2/m : P21/b
2.BA.10DigeniteCu9S5Trig. 3m (3 2/m) : R3m
2.BA.10AniliteCu7S4Orth. mmm (2/m 2/m 2/m) : Pnma
2.BA.15BorniteCu5FeS4Orth. mmm (2/m 2/m 2/m) : Pbca
2.BA.20BellidoiteCu2SeTet. 4/m : P42/n
2.BA.20BerzelianiteCu2-xSe (x ≈ 0.12)Iso. m3m (4/m 3 2/m) : Fm3m
2.BA.25AthabascaiteCu5Se4Orth.
2.BA.25UmangiteCu3Se2Tet. 4 2m : P4 21m
2.BA.30RickarditeCu7Te5Orth. mmm (2/m 2/m 2/m) : Pmmn
2.BA.30WeissiteCu2-xTeHex. 6/mmm (6/m 2/m 2/m) : P6/mmm
2.BA.35AcanthiteAg2SMon. 2/m : P21/m
2.BA.35SpryiteAg8(As3+0.5As5+0.5)S6Orth. mm2 : Pna21
2.BA.40dUM2003-13-S:AgAuCuAg6AuCu2S5
2.BA.40MckinstryiteAg5-xCu3+xS4Orth. mmm (2/m 2/m 2/m) : Pnma
2.BA.40StromeyeriteAgCuSOrth. mmm (2/m 2/m 2/m)
2.BA.42HoneaiteAu3TlTe2 Orth. mmm (2/m 2/m 2/m) : Pbcm
2.BA.45JalpaiteAg3CuS2Tet. 4/mmm (4/m 2/m 2/m) : I41/amd
2.BA.45SelenojalpaiteAg3CuSe2Tet. 4/mmm (4/m 2/m 2/m) : I41/amd
2.BA.45KuriliteAg8Te3SeTrig. 3 : R3
2.BA.47Spiridonovite(Cu1-xAgx)2TeTrig. 3m (3 2/m) : P3c1
2.BA.50WuyanzhiiteCu2STet. 4 2 2 : P43 21 2
2.BA.52ArgentiteAg2SIso.
2.BA.55NaumanniteAg2SeOrth. 2 2 2 : P21 21 21
2.BA.55AguilariteAg4SeSMon. 2/m
2.BA.60ChenguodaiteAg9Fe3+Te2S4Orth.
2.BA.60HessiteAg2TeMon. 2/m : P21/b
2.BA.60CervelleiteAg4TeSMon. 2/m
2.BA.65Henryite(Cu,Ag)3+xTe2 , with x ~ 0.40 Iso. m3m (4/m 3 2/m) : Fd3c
2.BA.65StĂŒtziteAg5-xTe3, x = 0.24-0.36Hex. 6 : P6
2.BA.70ArgyroditeAg8GeS6Orth. mm2 : Pna21
2.BA.70Putzite(Cu4.7Ag3.3)GeS6Iso. 4 3m : F4 3m
2.BA.70CanfielditeAg8SnS6Orth. mm2 : Pna21
2.BA.75FischesseriteAg3AuSe2Iso. 4 3 2 : I41 3 2
2.BA.75UytenbogaardtiteAg3AuS2Trig. 3m (3 2/m) : R3c
2.BA.75Penzhinite(Ag,Cu)4Au(S,Se)4Hex. 6 2 2 : P63 2 2
2.BA.75PetrovskaiteAuAgSMon.
2.BA.75PetziteAg3AuTe2Iso. 4 3 2 : I41 3 2
2.BA.80Bezsmertnovite(Au,Ag)4Cu(Te,Pb)Orth.
2.BA.80BilibinskitePbCu2Au3Te2Iso.
2.BA.80Bogdanovite(Au,Te,Pb)3(Cu,Fe)Iso.

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 EucairiteHide

References for EucairiteHide

Localities for EucairiteHide

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 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
 
  • La Rioja Province
    • Capital Department
      • Puerto Alegre
Paar (1996)
    • Chilecito department
      • Sañogasta
Brodtkorb (2002)
Anthony et al. (1990)
    • General Lamadrid department
Paar et al. (2004)
Marquez-Zavalia et al. (2021)
      • Villa Castelli
Simon et al. (1997)
Guerrero (1969)
de Brodtkorb et al. (2010)
Paar et al. (2005, January) +2 other references
Milka K. de BRODTKORB and Sabrina CROSTA (2010)
Paar et al. (2002) +1 other reference
Simon et al. (1997)
Recursos Minerales de la Republica ... +3 other references
    • Vinchina Department
      • JagĂŒĂ©
Grundmann et al. (2018)
  • Mendoza Province
    • LujĂĄn de Cuyo department
      • Cacheuta District
Simon et al. (1997) +1 other reference
          • Cerro de Cacheuta
Dana 6:53. +1 other reference
Australia
 
  • Queensland
    • Cook Shire
Segnit +1 other reference
  • South Australia
    • Pastoral Unincorporated Area
      • Iron Knob
Sorrell (n.d.)
  • Western Australia
    • Kalgoorlie-Boulder Shire
      • Kalgoorlie-Boulder
        • Kalgoorlie Consolidated Gold Mines
Simon et al. (1997)
Bulgaria
 
  • Sofia Province
    • Chelopech Municipality
Terziev (1966) +1 other reference
    • Etropole Municipality
Singer et al. (2008) +1 other reference
Canada
 
  • Nunavut
    • Kivalliq Region
      • Baker Lake
G.S.C. Bulletin 330. +1 other reference
  • Ontario
    • Cochrane District
      • Timmins
        • Kidd Township
Thorpe et al. (1976) +3 other references
  • Saskatchewan
    • Beaverlodge Lake area
Can Min 10:787-796
Canadian Mineralogist Vol. 10 (1972) +2 other references
Chile
 
  • Atacama
    • Chañaral Province
      • Salitrosa-Porvenir mining district
Atlas of Ore Minerals (1982)
China
 
  • Sichuan
    • Liangshan Yi
      • Huili County
Zhi Li et al. (1973) +2 other references
Czech Republic
 
  • Central Bohemian Region
Ć kĂĄcha et al. (2017)
  • Karlovy Vary Region
    • Karlovy Vary District
Anthony et al. (1990)
  • Olomouc Region
    • JesenĂ­k District
      • JavornĂ­k
        • ZĂĄlesĂ­
Sejkora et al. (2014)
  • Plzeƈ Region
    • Klatovy District
      • NalĆŸovskĂ© Hory
        • Ústaleč
Sejkora et al. (2022) +1 other reference
    • Tachov District
      • ZadnĂ­ Chodov
ScharmovĂĄ et al. (1995)
  • South Bohemian Region
    • PĂ­sek District
      • Kováƙov
        • Pƙedboƙice
Simon et al. (1997) +1 other reference
  • South Moravian Region
    • Brno-Country District
Ć ouba
  • Vysočina Region
    • ĆœÄĂĄr nad SĂĄzavou District
      • NovĂ© Město na Moravě
Kvaček +1 other reference
Kvaček +1 other reference
      • RoĆŸnĂĄ
        • RoĆŸnĂĄ deposit
Vavƙín +1 other reference
Kvaček (1979) +1 other reference
France
 
  • Auvergne-RhĂŽne-Alpes
    • Puy-de-DĂŽme
      • Issoire
        • Le Vernet-ChamĂ©ane
Simon et al. (1997)
Germany
 
  • Brandenburg
    • Spree-Neiße
      • Spremberg
Kopp et al. (2012)
  • Hesse
    • Darmstadt
      • Darmstadt-Dieburg
        • MĂŒhltal
          • Nieder-Ramstadt
Belendorff (2021)
  • Lower Saxony
    • Goslar District
      • Braunlage
        • St Andreasberg
Wittern (2001)
      • Harz (Landkreis Goslar)
Weiß (1990)
    • Göttingen District
      • Harz (Landkreis Göttingen)
Weiß (1990)
      • Walkenried
        • Zorge
Dr. GĂŒnter Grundmann collection
  • Saxony-Anhalt
    • Harz
      • Ballenstedt
        • Rieder
Schaarschmidt (2007) +1 other reference
    • Mansfeld-SĂŒdharz
      • Mansfeld
Wittern (2001)
  • Saxony
    • Erzgebirgskreis
      • Aue-Bad Schlema
Förster (2004) +2 other references
    • Zwickau District
      • Hartenstein
Forster et al. (2003)
Greenland
 
  • Kujalleq
    • Qaqortoq
Anthony et al. (1990) +1 other reference
Middle East
 
Vapnik et al. (2014)
Norway
 
  • Buskerud
    • Kongsberg
      • Underberget Mining Field
Pavel M. Kartashov analytical data (2005)
Poland
 
  • Lower Silesian Voivodeship
    • KƂodzko County
      • Gmina Stronie ƚląskie
Anthony et al. (1990)
    • WrocƂaw County
      • Gmina SobĂłtka
        • NasƂawice
Galuskin E. & SzeƂęg E. 2003: The first finding of Ag-amalgamates in rodingites (NasƂawice, Lower Silesia, Poland)
Romania
 
  • Hunedoara County
    • Certeju de Sus
www.minerals-of-the-carpathians +1 other reference
Sweden (TL)
 
  • Östergötland County
    • Valdemarsvik
[Zeitschrift fĂŒr Kristallographie et al. (1957) +3 other references
UK
 
  • England
    • Devon
      • Torbay
        • Torquay
Stanley et al. (1990) +1 other reference
USA
 
  • Colorado
    • Montrose County
      • Paradox Valley
Eckel et al. (1997)
    • San Miguel County
Eckel et al. (1997) +1 other reference
  • Idaho
    • Owyhee County
      • De Lamar Mining District
Collins (2012)
  • Nevada
    • Clark County
      • Spring Mountains
        • Goodsprings Mining District
Castor et al. (2004)
    • Elko County
      • Gold Circle Mining District (Midas Mining District)
Castor et al. (2004)
Tharalson +5 other references
    • Humboldt County
      • Sulphur Mining District
        • Sulphur
Castor et al. (2004)
  • Utah
    • San Juan County
      • La Sal Creek Mining District
Carter et al. (1965) +1 other reference
Uzbekistan
 
  • Navoiy
    • Central Kyzylkum Region
      • Bel'tau Mountains
Koneev et al. (2005)
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