Hostname: page-component-cd9895bd7-8ctnn Total loading time: 0 Render date: 2024-12-25T02:33:07.108Z Has data issue: false hasContentIssue false
  • English
  • Français

Colinowensite, BaCuSi2O6, a new mineral from the Kalahari Manganese Field, South Africa and new data on wesselsite, SrCuSi4O10

Published online by Cambridge University Press:  02 January 2018

B. Rieck ,
H. Pristacz  and
G. Giester
B. Rieck
Affiliation:
Institut für Mineralogie und Kristallographie, Universität Wien, Althanstrasse 14, A-1090 Vienna, Austria
H. Pristacz
Affiliation:
Institut für Mineralogie und Kristallographie, Universität Wien, Althanstrasse 14, A-1090 Vienna, Austria
G. Giester*
Affiliation:
Institut für Mineralogie und Kristallographie, Universität Wien, Althanstrasse 14, A-1090 Vienna, Austria
*
*E-mail: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

A new silicate, colinowensite, BaCuSi2O6, has been found in the Wessels mine, Kalahari Manganese Field, South Africa. It is associated with effenbergerite, wesselsite, lavinskyite, scottyite, diegogattaite, as well as with pectolite, quartz, aegirine, richterite, minerals of the garnet group and a number of different manganese and iron oxides, especially hausmannite and hematite. The mineral was named for the mineral collector and finder of the new species, Colin R. Owens, of Somerset West, South Africa. Colinowensite is brittle, with uneven fracture, and the estimated Mohs hardness is ∼4. It occurs as subhedral crystals <100 μm in size. The forms {100} and {110} are observed while {001} is always present in cleavage plates. The calculated density is 4.236 g cm–3. It is the natural analogue of the synthetic pigmentreferred to as Chinese or Han purple, which is found on artifacts from ancient and imperial China. The mineral is of dark blue to purple colour, with a purple streak, and is uniaxial (–), with ω = 1.740 (20), ε = 1.735 (20) (420 nm) and ω = 1.745 (20), ε = 1.730(20) (650 nm). The lustre is vitreous and no fluorescence is observed under either shortwave or longwave ultraviolet radiation. Avery strong pleochroism occurs from purple along the c axis to blue in a perpendicular direction. Colinowensite is not soluble in acids except HF. Electron microprobe analyses gave an average composition (wt.%) of CuO 22.53, BaO 43.43 and SiO2 34.04 yielding the empirical formula (based on 6 O a.p.f.u.) BaCuSi2O6. The new mineral is tetragonal, space group I41/acd with Z = 16, anda = 9.967(1), c = 22.290 (2) Å. Colinowensite is a cyclosilicate with [Si4O12]8– 4-membered single rings, arranged in sheets parallel to (001). The structure is further characterized by CuO4 squares sharing corners with four neighbouring silicate rings within a sheet. Ba2+ cations are bonded to ten O atoms in irregular coordination. Average Si–O, Cu–O and Ba–O bond lengths are 1.619, 1.934 and 2.943 Å, respectively. Colinowensite belongs to subdivision 9. CE of the Strunz Mineralogical Tables. In addition, based on single-crystal X-ray work, new structural data for wesselsite of chemical composition Sr0.9Ba0.1CuSi4O10 are provided.

Keywords

ColinowensiteBaCuSi2O6new mineralWessels MineKalahari Manganese FieldSouth AfricaWesselsiteSrCuSi4O10
Type
Research Article
Information
Mineralogical Magazine , Volume 79 , Issue 7 , December 2015 , pp. 1769 - 1778
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2015

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Berke, H. (2007) The invention of blue and purple pigments in ancient times. Chemical Society Reviews, 36, 15–30.CrossRefGoogle ScholarPubMed
Cairncross, B. and Beukes, N.J. (2013) The Kalahari Manganese Field: the Adventure Continues. Random House Struik, Capetown.Google Scholar
Chakoumakos, B.C., Fernandez-Baca, J.A. and Boatner, L.A. (1993) Refinement of the structures of the layer silicates MCuSi4O10 (M = Ca,Sr,Ba) by Rietveld analysis of neutron powder diffraction data. Journal of Solid State Chemistry, 103, 105–113.CrossRefGoogle Scholar
Chen, Y., Zhang, Y. and Feng, S. (2014) Hydrothermal synthesis and properties of pigments Chinese purple BaCuSi2O6 and dark blue BaCu2Si2O7 . Dyes and Pigments, 105, 167–173.CrossRefGoogle Scholar
Dowty, E. (2011) ATOMS for Windows V6.4.0. Shape Software, Kingsport, Tennessee, USA.Google Scholar
Finger, L.W., Hazen, R.M. and Hemley, R.J. (1989) BaCu Si2O6: a new cyclo silicate with four-membered tetrahedral rings. American Mineralogist, 74, 952–955.Google Scholar
Giester, G. and Rieck, B. (1994) Effenbergerite, BaCu [Si4O10], a new mineral from the Kalahari Manganese Field, South Africa: description and crystal structure. Mineralogical Magazine, 58, 663–670.CrossRefGoogle Scholar
Giester, G. and Rieck, B. (1996) Wesselsite, SrCu [Si4O10], a further new gillespite-group mineral from the Kalahari Manganese Field, South Africa. Mineralogical Magazine, 60, 795–798.CrossRefGoogle Scholar
Giester, G., Lengauer, C.L., Pristacz, H., Rieck, B., Topa, D. and von Bezing, K.L. (2016) Cairncrossite, a new Ca-Sr(-Na) phyllosilicate from the Wessels Mine, Kalahari Manganese Field, South Africa. European Journal of Mineralogy, DOI: 10.1127/ejm/2016/0028-2519CrossRefGoogle Scholar
Janczak, J. and Kubiak, R. (1992) Structure of the cyclic barium copper silicate Ba2Cu2[Si4O12] at 300 K. Acta Crystallographica, C48, 8–10.Google Scholar
Knight, K.S. and Henderson, C.M.B. (2007) Structural basis for the anomalous low-temperature thermal expansion behaviour of the gillespite-structured phase Ba0.5Sr0.5CuSi4O10. European Journal of Mineralogy, 19, 189–200.CrossRefGoogle Scholar
Knight, K.S., Henderson, C.M.B. and Clark, S.M. (2010) Structural variations in the wesselsite-effenbergerite (Sr1_xBaxCuSi401o) solid solution. European Journal of Mineralogy, 22, 411–123.CrossRefGoogle Scholar
Liu, Z., Mehta, A., Tamura, N., Pickard, D., Rong, B., Zhou, T. and Pianetta, P. (2007) Influence of Taoism on the invention of the purple pigment used on the Qin terracotta warriors. Journal of Archaeological Science, 34, 1878–1883.CrossRefGoogle Scholar
Malinovskii, Y.A. (1983) The crystal structure of Na2BaNd2(OH)2(Si4O12)(CO3). Doklady Akademii NaukSSSR, 272, 1375–1378.Google Scholar
Mandarino, J.A. (1981) The Gladstone-Dale relationship: Part IV The compatibility concept and its application. The Canadian Mineralogist, 70, 441–450.Google Scholar
Mazzi, F. and Rossi, G. (1980) The crystal structure of taramellite. American Mineralogist, 65, 123–128.Google Scholar
Miletich, R., Allan, D.R. and Angel, R.J. (1997) The synthetic Cr2+ silicates BaCrSi4O10 and SrCrSi4O10: the missing links in the gillespite-type ABSi4O10 series. American Mineralogist, 82, 697–707.CrossRefGoogle Scholar
Pabst, A., (1943) Crystal structure of gillespite, BaFeSi4O10 . American Mineralogist, 28, 372–390.Google Scholar
Pabst, A. (1959) Structures of some tetragonal sheet silicates. Acta Crystallographica, 12, 733–739.CrossRefGoogle Scholar
Pyatenko, Y.A., Zhdanova, T.A. and Voronkov, A.A. (1979) About the structure of K4Sc2(OH)2(Si4O12). Doklady Akademii Nauk SSSR, 248, 868–871.Google Scholar
Rieck, B. (2013) Colinowensite, IMA 2012-060. CNMNC Newsletter No. 15, February 2013, page 6; Mineralogical Magazine, 77, 1–12.Google Scholar
Rumsey, M.S., Welch, M.D., Kampf, A.R. and Spratt, J. (2013) Diegogattaite, Na2CaCu2Si8O20-H2O: a new nanoporous copper sheet silicate from Wessels Mine, Kalahari Manganese Fields, Republic of South Africa. Mineralogical Magazine, 77, 3155–3162.CrossRefGoogle Scholar
Sheldrick, G.M. (2008) A short history of SHELX. Acta Crystallographica, A64, 112–122.CrossRefGoogle Scholar
Sparta, K.M. and Roth, G. (2004) Reinvestigation of the structure of BaCuSi2O6 — evidence for a phase transition at high temperature. Acta Crystallographica, B60, 491–194.CrossRefGoogle Scholar
Strunz, H. and Nickel, E.H. (2001) Strunz Mineralogical Tables. Chemical-Structural Mineral Classification System. 9. Edition. E. Schweitzerbart'sche Verlagsbuchhandlung (Nägele und Obermiller), Stuttgart, Germany.Google Scholar
Xia, Y., Ma, Q.L., Zhang, Z.G., Liu, Z.D., Feng, J., Shao, A.D., Wang, W.F. and Fu, Q.L. (2014) Development of Chinese barium copper silicate pigments during the Qin Empire based on Raman and polarized light microscopy studies. Journal of Archaeological Science, 49, 500–509.CrossRefGoogle Scholar
Yang, H., Downs, R.T., Evans, S.H. and Pinch, W.W. (2013) Scottyite, the natural analog of synthetic BaCu2Si2O7, a new mineral from the Wessels mine, Kalahari Manganese Fields, South Africa. American Mineralogist, 98, 478–484.CrossRefGoogle Scholar
Yang, H., Downs, R.T., Evans, S.H. and Pinch, W.W. (2014) Lavinskyite, K(LiCu)Cu6(Si4O11)2(OH)4, iso- typic with planchéite, a new mineral from the Wessels mine, Kalahari Manganese Fields, South Africa. American Mineralogist, 99, 525–530.CrossRefGoogle Scholar
Zubkova, N.V., Pushcharovskii, D.Y., Giester, G., Tillmanns, E., Pekov, I.V and Krotova O.D. (2004) Crystal Structure of byelorussite-(Ce) NaMn Ba2Ce2(TiO)2[Si4O12]2(F,OH)-H2O. Crystallography Reports, 49, 964–968.CrossRefGoogle Scholar