Bornite

Bornite
Lightly iridescent bornite crystal on quartz needles, from Kazakhstan
Specimen size: 3.6 cm × 2.2 cm × 1.2 cm (1.42 in × 0.87 in × 0.47 in)
General
CategorySulfide mineral
Formula
(repeating unit)
Cu5FeS4
IMA symbolBn[1]
Strunz classification2.BA.10
Crystal systemOrthorhombic
Crystal classDipyramidal (mmm)
H-M symbol: (2/m 2/m 2/m)
Space groupPbca
Unit cella = 10.95 Å, b = 21.862 Å,
c = 10.95 Å; Z = 16
Identification
Formula mass501.88 g/mol
ColorCopper red, bronze brown, purple
Crystal habitGranular, massive, disseminated – Crystals pseudocubic, dodecahedral, octahedral
TwinningPenetration twins on [111]
CleavagePoor on [111]
FractureUneven to subconchoidal
TenacityBrittle
Mohs scale hardness3–3.25
LusterMetallic if fresh, iridescent tarnish
StreakGrayish black
Specific gravity5.06–5.08
Refractive indexOpaque
PleochroismWeak but noticeable
Other characteristicsMagnetic after heating, iridescent
References[2][3][4]

Bornite, also known as peacock ore, is a sulfide mineral with chemical composition Cu5FeS4 that crystallizes in the orthorhombic system (pseudo-cubic).

  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. ^ Barthelmy, David (2014). "Bornite Mineral Data". Webmineral.com. Retrieved 12 August 2022.
  3. ^ Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C. (2005). "Bornite" (PDF). Handbook of Mineralogy. Mineral Data Publishing. Retrieved 12 August 2022.
  4. ^ Bornite, Mindat.org, retrieved 12 August 2022