Hostname: page-component-78c5997874-j824f Total loading time: 0 Render date: 2024-11-20T05:35:08.675Z Has data issue: false hasContentIssue false

Namuwite, (Zn,Cu)4SO4(OH)6.4H2O, a new mineral from Wales

Published online by Cambridge University Press:  05 July 2018

Richard E. Bevins
Affiliation:
Department of Geology, National Museum of Wales, Cathays Park, Cardiff, CF1 3NP
Stephen Turgoose
Affiliation:
Department of Inorganic Chemistry, University College, PO Box 78, Cardiff, CF1 1XL
Peter A. Williams
Affiliation:
Department of Inorganic Chemistry, University College, PO Box 78, Cardiff, CF1 1XL

Abstract

Found on a specimen in the mineral collection of the National Museum of Wales, no. NMW 27.111.GR414, from the Aberllyn mine, Llanrwst mining field, North Wales, with hydrozincite on a breccia cemented by sphalerite, quartz, calcite, and ankerite. Atomic absorption and TGA analyses gave ZnO 37.8, CuO 22.0, SO3 14.9, H2O 24.5, total 99.2%, corresponding to (Zn2.50 Cu1.49)Σ3.99 S1.00 O7·7.32 H2O on the basis of total O = 7 in the anhydrous part. The ideal formula is (Zn,Cu)4SO4(OH)6·4H2O where Zn > Cu. It is hexagonal a 8.29, c 10.50 ± 0.01 Å, possible space groups P6, P, P6/m, P622, P6mm, Pm2, P2m, and P6/mmm. Isomorphous with synthetic Zn,SO4(OH)66·4H2O and (Zn,Cu)4SO4(OH)6·4H2O. Strongest X-ray powder diffractions are: 10.59(100)0001, 5.31(15)0002, 4.15(25)110, 2.71(42)210, 2.63(41)211,0004, 2.41(22)212, 1.57(23)322, 1.55(20)411. Namuwite is pale sea-green in colour, lustre pearly, streak very pale green, H (Mohs) 2. Cleavage {0001}, perfect. Density (g/cm3) 2.77 (meas.), 2.81 (calc. on the normalized empirical formula). It is optically uniaxial, sign not determined owing to the extremely low birefringence. Refractive index n = 1.577(5)(NaD). The mineral and name have been approved by the Commission on New Minerals and Mineral Names, IMA.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1982

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

Alwan, A. K., and Williams, P. A. (1979 Mineral. Mag. 43, 397–8.CrossRefGoogle Scholar
Dewey, H., and Smith, B. (1922 Special Rep. Mineral Resources G.B. 23.Google Scholar
Frias Ferreira da Rocha, M., and Glibert, J. (1972 Bull. Soc. Chim. Beiges, 81, 263–77.CrossRefGoogle Scholar
Glibert, J. (1977 Bull. Soc. Chim. Beiges, 86, 19.CrossRefGoogle Scholar
Howells, M. F., Leveridge, B. E., and Evans, C. D. R. (1971 Proc. Geol. Soc. Lond. 1664, 284–5.Google Scholar
Jacob, M., and Riquier, Y. (1969 A.T.B. Metallurgie, 10, 127–39.Google Scholar
Lecocq, R., Glibert, J., and Breckpot, R. (1971 Bull. Soc. Chim. Beiges, 80, 585–94.Google Scholar
Mann, A. W., and Deutscher, R. L. (1980 Chem. Geol. 29, 293311.CrossRefGoogle Scholar