Chanabayaite

Chanabayaite
General
Category Organic mineral
Formula
(repeating unit)		 Cu2(N3C2H2Cl(NH3,Cl,H2O,[])4
Crystal system Orthorhombic
Crystal class Dipyramidal (mmm)
H-M symbol: (2/m 2/m 2/m)
Space group Imma
Unit cell a = 19.48, b = 7.21,
c = 11.999 [Å] (approximated); Z = 4
Identification
Color Blue
Crystal habit Prisms (imperfect); radial aggregates
Cleavage (001), perfect; (100) and (010), imperfect
Tenacity Brittle
Mohs scale hardness 2
Density 1.48 (measured)
Pleochroism Deep blue to pale blue with gray hue (strong)
References [1][2][3]

Chanabayaite is the first recognized triazolate mineral, having the following 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 conctacts 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. 1 2 3 4 5 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. 1 2 "Chanabayaite: Chanabayaite mineral information and data". Mindat.org. Retrieved 2016-03-10.
  4. ↑ "Ammineite: Ammineite mineral information and data". Mindat.org. Retrieved 2016-03-10.
  5. ↑ "Joanneumite: Joanneumite mineral information and data". Mindat.org. Retrieved 2016-03-10.
  6. ↑ "Shilovite: Shilovite mineral information and data". Mindat.org. 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.
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