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Chalcocite

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About ChalcociteHide

Formula:
Cu2S
Colour:
Blue black, gray, black, black gray, or steel gray
Lustre:
Metallic
Hardness:
2½ - 3
Specific Gravity:
5.5 - 5.8
Crystal System:
Monoclinic
Name:
Named chalcosine in 1832 by François Sulpice Beudant from Greek, "chalkos", copper. This mineral was known by a wide variety of names previously. In 1868, James D. Dana and George J. Brush renamed this material "chalcocite".
Chalcocite-Digenite Group. Chalcocite-Yarrowite Series.

A secondary mineral in or near the oxidized zone of copper sulfide deposits. Hexagonal above 105°C ('High-chalcocite').
Easily confused with djurleite.

Small amounts of the Cu2S phase may deposit from supersaturated volcanic gas, as shown in an experiment (Africano et al., 2002; 300-700oC deposition range for this particular experiment).


Classification of ChalcociteHide

Approved, 'Grandfathered' (first described prior to 1959)
2.BA.05

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
2.4.7.1

2 : SULFIDES
4 : AmBnXp, with (m+n):p = 2:1
3.1.1

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

Pronounciation of ChalcociteHide

Pronounciation:
PlayRecorded byCountry
Jolyon & Katya RalphUnited Kingdom

Physical Properties of ChalcociteHide

Metallic
Transparency:
Opaque
Colour:
Blue black, gray, black, black gray, or steel gray
Streak:
Blackish lead gray
Hardness:
2½ - 3 on Mohs scale
Hardness:
VHN100=84 - 87 kg/mm2 - Vickers
Tenacity:
Brittle
Cleavage:
Poor/Indistinct
Indistinct on (110)
Fracture:
Conchoidal
Comment:
Somewhat sectile
Density:
5.5 - 5.8 g/cm3 (Measured)    5.8 g/cm3 (Calculated)

Optical Data of ChalcociteHide

Type:
Anisotropic
Anisotropism:
Weak

Chemical Properties of ChalcociteHide

Formula:
Cu2S
Common Impurities:
Fe

Crystallography of ChalcociteHide

Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P21/b
Setting:
P21/c
Cell Parameters:
a = 15.246(4) Å, b = 11.884(2) Å, c = 13.494(3) Å
β = 116.35(1)°
Ratio:
a:b:c = 1.283 : 1 : 1.135
Unit Cell V:
2,190.86 ų (Calculated from Unit Cell)
Twinning:
Common on {110} yielding pseudohexagonal stellate forms. Also on {032}, {112}.
Comment:
May be point group m and space group Pc; other monoclinic cell given: a = 11.82, b = 27.05, c = 13.43, β = 90°.

Crystallographic forms of ChalcociteHide

Crystal Atlas:
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Chalcocite no.48 - Goldschmidt (1913-1926)
Chalcocite - Penetration twin on {032}
Chalcocite - Multiple twin on {110}
3d models and HTML5 code kindly provided by www.smorf.nl.

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X-Ray Powder DiffractionHide

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Radiation - Copper Kα
Data Set:
Data courtesy of RRUFF project at University of Arizona, used with permission.
Powder Diffraction Data:
d-spacingIntensity
3.276 (35)
2.7256 (35)
2.4074 (50)
2.4030 (70)
1.9746 (70)
1.8811 (70)
1.8800 (100)
Comments:
Similar to djurleite.

Synonyms of ChalcociteHide

Other Language Names for ChalcociteHide

Varieties of ChalcociteHide

Argentiferous ChalcociteA silver-bearing variety of chalcocite.
DucktowniteBlackish chalcocite coating or enclosing crystals or grains of Pyrite.
Originally described from Ducktown mine, Ducktown, Ducktown District, Polk Co., Tennessee, USA.
Harrisite (of Dana)Pseudomorph of chalcocite after galena.
At the Osarizawa mine, Japan, djurleite pseudos after galena were also called "harrisite" (Alfredo Petrov).

Note that Harrisite is also a rock name.
Para-KupferglanzParamorphs of Chalcocite after High-Chalcocite

Relationship of Chalcocite to other SpeciesHide

Structurally related to group(s):
Forms a series with:

Common AssociatesHide

Associated Minerals Based on Photo Data:
Calcite111 photos of Chalcocite associated with Calcite on mindat.org.
Quartz98 photos of Chalcocite associated with Quartz on mindat.org.
Bornite92 photos of Chalcocite associated with Bornite on mindat.org.
Malachite85 photos of Chalcocite associated with Malachite on mindat.org.
Chalcopyrite79 photos of Chalcocite associated with Chalcopyrite on mindat.org.
Djurleite51 photos of Chalcocite associated with Djurleite on mindat.org.
Pyrite46 photos of Chalcocite associated with Pyrite on mindat.org.
Chrysocolla31 photos of Chalcocite associated with Chrysocolla on mindat.org.
Covellite28 photos of Chalcocite associated with Covellite on mindat.org.
Silver18 photos of Chalcocite associated with Silver on mindat.org.

Related Minerals - Nickel-Strunz GroupingHide

2.BA.AlburniteAg8GeTe2S4Iso.
2.BA.DzierżanowskiteCaCu2S2Trig. 3m (3 2/m) : P3m1
2.BA.05DjurleiteCu31S16Mon. 2/m
2.BA.05GeeriteCu8S5Trig. 3
2.BA.05RoxbyiteCu9S5Tric. 1 : P1
2.BA.10AniliteCu7S4Orth. mmm (2/m 2/m 2/m) : Pnma
2.BA.10DigeniteCu9S5Trig. 3m (3 2/m) : R3m
2.BA.15BorniteCu5FeS4Orth. mmm (2/m 2/m 2/m) : Pbca
2.BA.20BellidoiteCu2SeTet. 4/m : P42/n
2.BA.20BerzelianiteCu2SeIso. m3m (4/m 3 2/m) : Fm3m
2.BA.25AthabascaiteCu5Se4Orth.
2.BA.25UmangiteCu3Se2Tet.
2.BA.30RickarditeCu7Te5Orth.
2.BA.30WeissiteCu2-xTeHex.
2.BA.35AcanthiteAg2SMon. 2/m : P21/m
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.40dUM2003-13-S:AgAuCuAg6AuCu2S5
2.BA.45JalpaiteAg3CuS2Tet.
2.BA.45SelenojalpaiteAg3CuSe2Tet. 4/mmm (4/m 2/m 2/m) : I41/amd
2.BA.50EucairiteAgCuSeOrth.
2.BA.55AguilariteAg4SeSMon. 2/m
2.BA.55NaumanniteAg2SeOrth. 2 2 2 : P21 21 21
2.BA.60CervelleiteAg4TeSMon. 2/m
2.BA.60HessiteAg2TeMon. 2/m : P21/b
2.BA.60ChenguodaiteAg9Fe3+Te2S4Orth.
2.BA.65Henryite(Cu,Ag)3+xTe2 , with x ~ 0.40 Iso. m3m (4/m 3 2/m) : Fd3c
2.BA.65StütziteAg5-xTe3, x = 0.24-0.36Hex. 6 : P6
2.BA.70ArgyroditeAg8GeS6Orth. mm2 : Pna21
2.BA.70CanfielditeAg8SnS6Orth. mm2
2.BA.70Putzite(Cu4.7Ag3.3)GeS6Iso. 4 3m : F4 3m
2.BA.75FischesseriteAg3AuSe2Iso. 4 3 2 : I41 3 2
2.BA.75Penzhinite(Ag,Cu)4Au(S,Se)4Hex.
2.BA.75PetrovskaiteAuAg(S,Se)Mon.
2.BA.75PetziteAg3AuTe2Iso. 4 3 2 : I41 3 2
2.BA.75UytenbogaardtiteAg3AuS2Trig. 3m (3 2/m) : R3c
2.BA.80Bezsmertnovite(Au,Ag)4Cu(Te,Pb)Orth.
2.BA.80BilibinskitePbCu2Au3Te2Iso.
2.BA.80Bogdanovite(Au,Te,Pb)3(Cu,Fe)Iso.

Related Minerals - Dana Grouping (8th Ed.)Hide

2.4.7.2DjurleiteCu31S16Mon. 2/m
2.4.7.3DigeniteCu9S5Trig. 3m (3 2/m) : R3m
2.4.7.4RoxbyiteCu9S5Tric. 1 : P1
2.4.7.5AniliteCu7S4Orth. mmm (2/m 2/m 2/m) : Pnma
2.4.7.7SpionkopiteCu39S28Trig.

Related Minerals - Hey's Chemical Index of Minerals GroupingHide

3.1.2DjurleiteCu31S16Mon. 2/m
3.1.3DigeniteCu9S5Trig. 3m (3 2/m) : R3m
3.1.4AniliteCu7S4Orth. mmm (2/m 2/m 2/m) : Pnma
3.1.5RoxbyiteCu9S5Tric. 1 : P1
3.1.6SpionkopiteCu39S28Trig.
3.1.7GeeriteCu8S5Trig. 3
3.1.8CovelliteCuSHex. 6/mmm (6/m 2/m 2/m) : P63/mmc
3.1.9BerzelianiteCu2SeIso. m3m (4/m 3 2/m) : Fm3m
3.1.10BellidoiteCu2SeTet. 4/m : P42/n
3.1.11UmangiteCu3Se2Tet.
3.1.12YarrowiteCu9S8Trig.
3.1.13AthabascaiteCu5Se4Orth.
3.1.14KlockmanniteCuSeHex. 6/mmm (6/m 2/m 2/m) : P63/mmc
3.1.15Krut'aiteCuSe2Iso. m3 (2/m 3) : Pa3
3.1.16WeissiteCu2-xTeHex.
3.1.17RickarditeCu7Te5Orth.
3.1.18VulcaniteCuTeOrth.
3.1.19BambollaiteCu(Se,Te)2Tet.
3.1.20LautiteCuAsSOrth. mmm (2/m 2/m 2/m) : Pnma
3.1.21MgriiteCu3AsSe3
3.1.22CubaniteCuFe2S3Orth. mmm (2/m 2/m 2/m)
3.1.23BorniteCu5FeS4Orth. mmm (2/m 2/m 2/m) : Pbca
3.1.24FukuchiliteCu3FeS8Iso. m3 (2/m 3) : Pa3
3.1.25ChalcopyriteCuFeS2Tet. 4 2m : I4 2d
3.1.26MooihoekiteCu9Fe9S16Tet.
3.1.27HaycockiteCu4Fe5S8Orth. 2 2 2
3.1.28IsocubaniteCuFe2S3Iso. m3m (4/m 3 2/m) : Fm3m
3.1.29IdaiteCu5FeS6Hex.
3.1.30NukundamiteCu3.4Fe0.6S4Trig. 3m (3 2/m) : P3m1
3.1.31PutoraniteCu1.1Fe1.2S2Iso.
3.1.32Orickite2CuFeS2 · H2OHex.
3.1.33EskeborniteCuFeSe2Tet.
3.1.34Chaméanite(Cu,Fe)4As(Se,S)4Iso.
3.1.35TalnakhiteCu9(Fe,Ni)8S16Iso. 4 3m : I4 3m

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.

Chalcocite in petrologyHide

An essential component of rock names highlighted in red, an accessory component in rock names highlighted in green.

References for ChalcociteHide

Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
Palache, Charles, Harry Berman & Clifford Frondel (1944) The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana Yale University 1837-1892, Volume I: Elements, Sulfides, Sulfosalts, Oxides. John Wiley and Sons, Inc., New York. 7th edition, revised and enlarged, 834pp.: 187-190.
Zeitschrift für Kristallographie 150, 299-320.
Cook, W.R. (1972) Instability of chalcocite. Mineralogical Record 3, 15.
Pósfai, M. & Buseck, P. R. (1994) Djurleite, digenite, and chalcocite: Intergrowths and transformations. American Mineralogist, 79, 308-315.
Africano, F., Van Rompaey, G., Bernard, A., Le Guern, F. (2002) Deposition of trace elements from high temperature gases of Satsuma-Iwojima volcano. Earth Planets Space: 54: 275-286.

Internet Links for ChalcociteHide

Localities for ChalcociteHide

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