Reference:
▪ Bojar, H.-P., Walter, F., Baumgartner, J. (2017): Joanneumite, Cu(C3N3O3H2)2(NH3)2, a new mineral from Pabellón de Pica, Chile and the crystal structure of its synthetic analogue. Mineralogical Magazine, 81, 155–166.
Abstract:
The new mineral joanneumite from the type locality Pabellón de Pica Mountain, Iquique Province, Tarapacá Region, Chile, was investigated. There it occurs as violet microcrystalline aggregates up to two millimetres in small cracks of a gabbroic rock, which is covered by a guano deposit. Associated minerals are salammoniac, dittmarite, möhnite and gypsum. Joanneumite is non-fluorescent and the Mohs hardness is 1. The calculated density is 2.020 g cm-3. The infrared spectrum of joanneumite shows the frequencies of NH3- and isocyanurate groups and the absence of absorptions of H2O molecules and OH− ions. The chemical composition (electron microprobe data, the hydrogen was calculated from the structural formula, wt%) is C 20.33, N 31.11, O 28.34, Cu 17.27, Zn 0.24, H 2.82, total 100.11. The empirical formula is Cu0.96Zn0.01N7.84C5.98O6.25H9.96 and the idealized formula is CuN8C6O6H10 with the structural formula Cu(C3N3O3H2)2(NH3)2. The synthetic analogue of joanneumite was prepared for the single crystal structure refinement due to the lack of suitable single crystals. The crystal structure was solved and refined to R = 0.025 based upon 1166 unique reflections with I>2σ(I). Joanneumite is triclinic, space group P⎯1, a = 4.982(1), b = 6.896(1), c = 9.115(2) Å, α = 90.53(3), β = 97.85(3), γ = 110.08(3)°, V = 290.8(1) Å3, Z = 1 obtained from single crystal data at 100 K, which are in good agreement with cell parameters from powder diffraction data of joanneumite at 293 K: a = 5.042(1), b = 6.997(1), c = 9.099(2) Å, α = 90.05(3), β = 98.11(2), γ = 110.95(3)° and V = 296.3(1) Å3. The eight strongest lines of the powder X-ray diffraction pattern [d, Å (I,%) (hkl)] are 6.52 (68) (010), 5.15 (47) (011), 4.66 (21) (100,-110), 4.35 (9) (-111), 3.29 (6) (-120), 3.22 (7) (-1-11), 3.140 (100) (-121), 2.074 (7) (-132). The crystal structure of joanneumite is identic with the structure of synthetic bis(isocyanurato)diamminecopper(II).
▪ Bojar, H.-P., Walter, F., Baumgartner, J. (2017): Joanneumite, Cu(C3N3O3H2)2(NH3)2, a new mineral from Pabellón de Pica, Chile and the crystal structure of its synthetic analogue. Mineralogical Magazine, 81, 155–166.
Abstract:
The new mineral joanneumite from the type locality Pabellón de Pica Mountain, Iquique Province, Tarapacá Region, Chile, was investigated. There it occurs as violet microcrystalline aggregates up to two millimetres in small cracks of a gabbroic rock, which is covered by a guano deposit. Associated minerals are salammoniac, dittmarite, möhnite and gypsum. Joanneumite is non-fluorescent and the Mohs hardness is 1. The calculated density is 2.020 g cm-3. The infrared spectrum of joanneumite shows the frequencies of NH3- and isocyanurate groups and the absence of absorptions of H2O molecules and OH− ions. The chemical composition (electron microprobe data, the hydrogen was calculated from the structural formula, wt%) is C 20.33, N 31.11, O 28.34, Cu 17.27, Zn 0.24, H 2.82, total 100.11. The empirical formula is Cu0.96Zn0.01N7.84C5.98O6.25H9.96 and the idealized formula is CuN8C6O6H10 with the structural formula Cu(C3N3O3H2)2(NH3)2. The synthetic analogue of joanneumite was prepared for the single crystal structure refinement due to the lack of suitable single crystals. The crystal structure was solved and refined to R = 0.025 based upon 1166 unique reflections with I>2σ(I). Joanneumite is triclinic, space group P⎯1, a = 4.982(1), b = 6.896(1), c = 9.115(2) Å, α = 90.53(3), β = 97.85(3), γ = 110.08(3)°, V = 290.8(1) Å3, Z = 1 obtained from single crystal data at 100 K, which are in good agreement with cell parameters from powder diffraction data of joanneumite at 293 K: a = 5.042(1), b = 6.997(1), c = 9.099(2) Å, α = 90.05(3), β = 98.11(2), γ = 110.95(3)° and V = 296.3(1) Å3. The eight strongest lines of the powder X-ray diffraction pattern [d, Å (I,%) (hkl)] are 6.52 (68) (010), 5.15 (47) (011), 4.66 (21) (100,-110), 4.35 (9) (-111), 3.29 (6) (-120), 3.22 (7) (-1-11), 3.140 (100) (-121), 2.074 (7) (-132). The crystal structure of joanneumite is identic with the structure of synthetic bis(isocyanurato)diamminecopper(II).