Original paper
Redefinition of namibite, Cu(BiO)2VO4OH
Mrázek, Zdeněk; Moravcová, Hana; Ondruš. Petr,
Neues Jahrbuch für Mineralogie - Monatshefte Jg. 1994 Heft 11 (1994), p. 481 - 488
5 references
published: Nov 18, 1994
DOI: 10.1127/njmm/1994/1994/481
ArtNo. ESP156199411001, Price: 19.00 €
Abstract
The second occurrence of namibite was found at Jáchymov, Krušné hory Mts., Czech Republic. Wet chemical analysis (CuO 12.03, Bi2O372.24, V2O5 13.77, H2O 1.51, sum. 99.55%) and infrared study show that namibite is a hydroxo-vanadate of copper and bismuth and its formula is Cu(BiO)2VO4OH. The unit cell dimensions are: a = 11.877 (2), b = 3.702 (1), c = 7.497 (1) Å,ß = 109.76 (1)°, Dcalc = 6. 91 g/cm3. TG curve shows two mass decreases at 430-490°C (1.5%-water) and 810-880 °C (0.64 %-oxygen). They correspond to the endothermic peaks on the DTA curve at 463 and 796 °C. Indexed powder diffraction data and IR absorption spectra of namibite from Jáchymov and of synthetic hydrothermal namibite are given. This mineral was found with eulytite, beyerite, bismuthite and pucherite within fragments of quartz veins.
Keywords
Namibite • redefinition • synt. Cu (BiO)2VO4OH • Jáchymov • Czech Republic