Chalcocite

Chalcocite
Chalcocite from Cornwall
General
CategorySulfide minerals
Formula
(repeating unit)
copper(I) sulfide: Cu2S
IMA symbolCc[1]
Strunz classification2.BA.05a
Crystal systemMonoclinic
Crystal classPrismatic (2/m)
(same H-M symbol)
Space groupP21/c
Unit cella = 15.246(4) Å,
b = 11.884(2) Å,
c = 13.494(3) Å;
β = 116.35(1)°; Z = 48
Identification
ColorDark gray to black
Crystal habitTabular to prismatic crystals also massive to granular, (pseudo-orthorhombic)
TwinningCommon on {110} yielding pseudohexagonal stellate forms
CleavageIndistinct on {110}
FractureConchoidal
TenacityBrittle to sectile
Mohs scale hardness2+12–3
LusterMetallic
StreakShiny black to lead gray
DiaphaneityOpaque
Specific gravity5.5–5.8
Fusibility2–2.5
References[2][3][4][5]

Chalcocite (/ˈkælkəˌst/),[6][7] copper(I) sulfide (Cu2S), is an important copper ore mineral. It is opaque and dark gray to black, with a metallic luster. It has a hardness of 2.5–3 on the Mohs scale. It is a sulfide with a monoclinic crystal system.

The term chalcocite from the Greek khalkos, meaning "copper". It is also known as redruthite, vitreous copper, or copper-glance.[8]

  1. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ Mineralienatlas
  3. ^ Mindat.org
  4. ^ Webmineral.com
  5. ^ Handbook of Mineralogy
  6. ^ "chalcocite". CollinsDictionary.com. HarperCollins.
  7. ^ "chalcocite". Dictionary.com Unabridged (Online). n.d.
  8. ^ Chisholm, Hugh, ed. (1911). "Copper-glance" . Encyclopædia Britannica. Vol. 7 (11th ed.). Cambridge University Press. p. 110.