Chemistry:Chanabayaite

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Chanabayaite
Chanabayaite.jpg
General
CategoryOrganic mineral
Formula
(repeating unit)
Cu2(N3C2H2Cl(NH3,Cl,H2O,[])4
Crystal systemOrthorhombic
Crystal classDipyramidal (mmm)
H-M symbol: (2/m 2/m 2/m)
Space groupImma
Unit cella = 19.48, b = 7.21,
c = 11.999 [Å] (approximated); Z = 4
Identification
ColorBlue
Crystal habitPrisms (imperfect); radial aggregates
Cleavage(001), perfect; (100) and (010), imperfect
TenacityBrittle
Mohs scale hardness2
Density1.48 (measured)
PleochroismDeep blue to pale blue with gray hue (strong)
References[1][2][3]

Chanabayaite is the first recognized triazolate mineral, having the formula Cu2(N3C2H2Cl(NH3,Cl,H2O,[])4.

Minor iron admixture is also present.[2] It is also one of a few currently known minerals containing ammine groups, including also ammineite, joanneumite and shilovite.[4][5][6] All the minerals are rare and were found in a single guano deposit in Chile, called Pabellón de Pica.[3] A similar natural phase, formula NaCu2Cl3[N3C2H2]2[NH3]2•4H2O, likely a precursor of chanabayaite, is described by Zubkova et al. 2016.[7]

Crystal structure

The main features of the crystal structure of chanabayaite are:[2]

  • copper forms octahedra, part of which share corners
  • 1,2,4-triazolate anions link the octahedra

Association

Chanabayaite coexists with halite, joanneumite, nitratine, salammoniac and paragenetically-unrelated chalcopyrite. Chalcopyrite is present in an amphibole- and plagioclase-bearing gabbro, that contacts the guano deposit.[2]

Formation

Three suggested processes account for the formation of chanabayaite:[2]

  • leaching of sodium from the precursor phase
  • leaching of chlorine from the precursor phase
  • partial dehydratation of the precursor phase

References

  1. Mineralienatlas
  2. 2.0 2.1 2.2 2.3 2.4 Chukanov, N.V., Zubkova, N.V., Möhn, G., Pekov, I.V., Pushcharovsky, D.Yu., and Zadov, A.E., 2015. Chanabayaite, Cu2(N3C2H2Cl(NH3,Cl,H2O,[])4, a new mineral containing triazolate anion. Geology of Ore Deposits 57(8), 712-720.
  3. 3.0 3.1 "Chanabayaite: Chanabayaite mineral information and data". http://www.mindat.org/min-43945.html. Retrieved 2016-03-10. 
  4. "Ammineite: Ammineite mineral information and data". http://www.mindat.org/min-38895.html. Retrieved 2016-03-10. 
  5. "Joanneumite: Joanneumite mineral information and data". http://www.mindat.org/min-42755.html. Retrieved 2016-03-10. 
  6. "Shilovite: Shilovite mineral information and data". http://www.mindat.org/min-46139.html. Retrieved 2016-03-10. 
  7. Zubkova, N.V., Chukanov, N.V., Pekov, I., and Pushcharovsky, D., 2016. The crystal structure of the natural 1,2,4-triazolate compound NaCu2Cl3[N3C2H2]2[NH3]2•4H2O. Zeitschrift für Kristallographie - Crystalline Materials 231(1), 47–53.