Mimetit z ložiska Ján Nepomuk pri Veľkom Poli (Slovenská republika)

A new occurrence of mimetite was recently discovered at the abandoned Ján Nepomuk Pb-Ag deposit near Veľké Pole, Žarnovica Co., Banská Bystrica Region, Slovakia. It forms light to bright yellow, prismatic crystals reaching up to 5 mm in size. Mimetite occurs in fractures and cavities of strongly altered and limonitised limestone with impregnations and relicts of primary galena and pyrite. It is associated with cerussite and calcite. The refined unit-cell parameters (for the hexagonal space group P63/m) are a 10.2437(4) Å, c 7.4437(6) Å and V 676.44(6) Å3. Except of dominant contents of Pb, As and Cl only minor amounts of Ca (up to 0.36 apfu), Al (up to 0.03 apfu), P (up to 0.03 apfu) and V (up to 0.02 apfu) were detected in four mimetite samples studied by EMPA-WDS.