Natrodufrénite from Vlastkovec near Slavonice, Moravia, Czech Republic

Acta Mus. Moraviae, Sci. Geol. 107 (2022), issue 2, pages 145-154

Article

Authors:

Vrtiška, L., Malíková, R., Dolníček, Z., Sejkora, J.

Abstract:

Natrodufrénite from Vlastkovec near Slavonice, Moravia, Czech Republic

Secondary phosphate, natrodufrénite, was found on historical samples from Stříbrný vrch near Vlastkovec, Moravia (Czech Republic). Natrodufrénite forms crusts of dark green to blue-green radial aggregates up to 0.3 mm in size with silky lustre on fissures and in cavities of gangue quartz. Its chemical composition corresponds to empirical formula:(Na_0.92Ca_0.05□_0.06)_Σ1.03(Fe²⁺_0.86Zn_0.07Mg_0.01)_Σ0.94(Fe³⁺_4.71Al_0.29)_Σ5.00[(PO₄)_3.99(AsO₄)_0.01]_Σ4.00(OH)_5.90·2H₂O. Natrodufrénite is monoclinic, space group C2/c, unit-cell parameters refined from X-ray powder diffraction data are a 25.88(6), b 5.138(6), c 13.785(3) Å, β 111.5(2)°and V 1704.7(6) Å³.

Contact:

Luboš Vrtiška, Department of Mineralogy and Petrology, National Museum, Cirkusová 1740, 193 00 Praha 9 – Horní Počernice, Czech Republic; e-mail: lubos.vrtiska@nm.cz
Radana Malíková, Department of Mineralogy and Petrology, National Museum, Cirkusová 1740, 193 00 Praha 9 – Horní Počernice, Czech Republic
Zdeněk Dolníček, Department of Mineralogy and Petrology, National Museum, Cirkusová 1740, 193 00 Praha 9 – Horní Počernice, Czech Republic
Jiří Sejkora, Department of Mineralogy and Petrology, National Museum, Cirkusová 1740, 193 00 Praha 9 – Horní Počernice, Czech Republic

Citation:

Vrtiška, L., Malíková, R., Dolníček, Z., Sejkora, J., 2022: Natrodufrénit z Vlastkovce u Slavonic, Morava, Česká republika. – Acta Mus. Morav., Sci. Geol., 107, 2, 145–154 (with English summary)

Keywords:

chemical composition, Czech Republic, Moravia, natrodufrenite, phosphate occurrence, Vlastkovec, X-ray powder diffraction data

ISSN: 1211–8796