Skip to main content Accessibility help
×
Home

X-ray diffraction study of middlebackite [CuII2C2O4(OH)2, di-copper oxalate dihydroxide], using a mineral specimen from Mooloo Downs Station, Western Australia and chemically synthesized material

  • B. H. O'Connor (a1), R. M. Clarke (a2), J. A. Kimpton (a3) and D. G. Allen (a4)

Abstract

Additional crystallographic data are given for the recently reported mineral middlebackite, which has been described for discoveries at Iron Knob in South Australia and Passo di San Lugano near Trento, Italy. The material examined in the present study was from a third finding of the mineral, viz. from a quartz outcrop at Mooloo Downs Station in Western Australia within which it was co-located with the chemically- and structurally-related mineral moolooite, CuIIC2O4·nH2O, reported by Clarke and Williams (1986). In this study, the crystal structure was elucidated independently of the other studies using a combination of the a priori charge flipping and simulated annealing methods with synchrotron radiation diffraction (SRD) powder data. The principal crystal data for the Mooloo Downs material are: space group P21/c with lattice parameters a = 7.2659(18) Å, b = 5.7460(11) Å, c = 5.6806(11) Å, β = 104.588(3)°; Vc = 229.46(18) Å3; empirical formula CuII2C2O4(OH)2 with 2 formula units per unit cell; and calculated density = 3.605 g cm−3. The lattice parameters agree approximately with values given for the other studies, but not within the reported error estimates. The atom coordinates, interatomic distances, and angles for the Mooloo Downs material are compared with those from the other studies using single crystal data, with the values from all three studies agreeing approximately, but again not within the reported uncertainties. The crystal chemistry found for middlebackite received strong confirmation through the synthesis for the first time of di-copper oxalate di-hydroxide. Laboratory X-ray diffraction powder data for the synthetic form of the mineral from this study agree closely with the SRD data for the natural mineral.

Copyright

Corresponding author

a)Author to whom correspondence should be addressed. Electronic mail: brian_oconnor@iprimus.com.au

References

Hide All
Chisholm, J. E., Jones, G. C., and Purvis, G. W. (1987). “Hydrated copper oxalate, moolooite, in lichens,” Mineral. Mag. 51, 715718.
Christensen, A. N., Lebech, B., Andersen, N. H., and Grivel, J-C. (2014). “The crystal structure of paramagnetic copper (II) oxalate (CuC2O4): formation and thermal decomposition of randomly-stacked anisotropic nano-sized crystallites,” Dalton Trans. 43, 1675416768.
Clarke, R. M. and O'Connor, B. H. (2019). “New mineralogical data for the mineral middlebackite [Cu2C2O4(OH)2], discovered at Moolooo Downs, Western Australia,” Austral. J. Mineral.
Clarke, R. M. and Williams, I. R. (1986). “Moolooite, a naturally occurring hydrated copper oxalate from Western Australia,” Mineral. Mag. 50, 295298.
Coelho, A. A. (2000). “Whole-profile structure solution from powder diffraction data using simulated annealing,” J. Appl. Crystallogr. 33, 899908.
Demartin, F., Campostrini, I, Ferretti, P., and Rocchetti, I. (2017). “Second global occurrence of middlebackite near the Passo di San Lugano (Carano, Trento, Italy),” Geol. Alp. 14, 3538.
Demartin, F., Campostrini, I, Ferretti, P., and Rocchetti, I. (2018). “Fiemmeite Cu2(C2O4)(OH)2·2H2O, a new mineral from Val di Fiemme, Trentino, Italy,” Minerals 8, 248.
Elliott, P. (2016). “‘Middlebackite, IMA 2015-115’, CNMNC Newsletter No 30, April 2016, page 411,” Mineral. Mag. 80, 407413.
Elliott, P. (2018). “Middlebackite, a new Cu oxalate mineral from Iron Monarch, South Australia: description and crystal structure,” Pre-published accepted article, Mineral. Mag., doi: 10.1180/mgm.2018.136.
Fichtner-Schmittler, H. (1979). “On some features of X-ray powder patterns of OD structures,” Crystallogr. Res. Technol 14, 10791088.
Fomina, M., Hillier, S., Charnock, J. M., Melville, K, Alexander, I.J., and Gadd, G. M. (2005). “Role of oxalic acid overexcretion in transformations of toxic metal minerals by Beauveria caledonica,” Appl. Environ. Microbiol. 71, 371381.
Frost, R. L., Jing, Y., and Ding, Z. (2003). “Raman and FTIR spectroscopy of natural oxalates: implications for evidence of life on Mars,” Chin. Sci. Bull. 48, 18441852.
Grice, J. D. and Gasparrini, E. (1981). “Spertiniite, a new mineral from the Jeffrey Mine, Quebec,” Can. Mineral. 19, 337340.
Hill, R. J. and Flack, H. D. (1987). “The use of the Durbin-Watson d statistic in Rietveld analysis,” J. Appl. Crystallogr. 20, 356361.
O'Connor, B. H., Clarke, R. M. and Kimpton, J. R. (2019). “Synchrotron radiation diffraction study of the mineral moolooite, CuC2O4.0.44H2O, and synthetic Cu oxalates,” Powder Diffr., 34, 2134.
Oswald, H. R., Reller, A, Schmalle, H. W., and Dubler, E. (1990). “Structure of copper (II) hydroxide, Cu(OH)2,” Acta Crystallogr., Sect. C, 46, 22792284.
Palatinus, L. and Chapuis, G. (2007). “SUPERFLIP - a computer program for the solution of crystal structures by charge flipping in arbitrary dimensions,” J. Appl. Crystallogr. 40, 786790.
Purvis, G. W. (1984). “The occurrence of copper oxalate in lichens growing on copper-sulphide-bearing rocks in Scandinavia,” Lichenologist 16, 197204.
Schmitt, B., Bronnimann, C, Eikenberry, E. F., Gozzo, F., Horrmann, C., Horisberger, R., and Patterson, B. (2003). “Mythen detector system,” Nucl. Instrum. Methods Phys. Res., Sect. A 501, 267272.
Schmittler, H. (1968). “Structural principle of disordered copper(II) oxalate (CuC2O4.nH2O),” Monatsber. Dtsch. Akad. Wiss. Berlin 10, 581604.
Wilson, A. J. C. (ed.) (1995). International Tables for Crystallography. Volume C: Mathematical, Physical and Chemical Tables (Kluwer Academic Publishers, Dordrecht), p. 751.

Keywords

Type Description Title
UNKNOWN
Supplementary materials

O'Connor et al. supplementary material
O'Connor et al. supplementary material 1

 Unknown (16 KB)
16 KB
UNKNOWN
Supplementary materials

O'Connor et al. supplementary material
O'Connor et al. supplementary material 2

 Unknown (57 KB)
57 KB
UNKNOWN
Supplementary materials

O'Connor et al. supplementary material
O'Connor et al. supplementary material 3

 Unknown (705 KB)
705 KB

X-ray diffraction study of middlebackite [CuII2C2O4(OH)2, di-copper oxalate dihydroxide], using a mineral specimen from Mooloo Downs Station, Western Australia and chemically synthesized material

  • B. H. O'Connor (a1), R. M. Clarke (a2), J. A. Kimpton (a3) and D. G. Allen (a4)

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed