minerals Article Chemical Composition of Mn- and Cl-Rich Apatites from the Szklary Pegmatite, Central Sudetes, SW Poland: Taxonomic and Genetic Implications Adam Szuszkiewicz 1,* ID , Adam Pieczka 2, Bozena˙ Goł˛ebiowska 2, Magdalena Duma ´nska-Słowik 2 ID , Mariola Marszałek 2 and Eligiusz Szeł˛eg 3 1 Institute of Geological Sciences, University of Wrocław, pl. M. Borna 9, 50-204 Wrocław, Poland 2 Department of Mineralogy, Petrography and Geochemistry, AGH University of Science and Technology Mickiewicza 30, 30-059 Kraków, Poland;
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[email protected] (M.M.) 3 Department of Geochemistry, Mineralogy and Petrography, Faculty of Earth Sciences, University of Silesia, B˛edzi´nska60, 41-200 Sosnowiec, Poland;
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[email protected] Received: 6 July 2018; Accepted: 9 August 2018; Published: 14 August 2018 Abstract: Although calcium phosphates of the apatite group (apatites) with elevated contents of Mn are common accessory minerals in geochemically evolved granitic pegmatites, their Mn-dominant M1 M2 X analogues are poorly studied. Pieczkaite, Mn2 Mn3(PO4)3 Cl, is an exceptionally rare Mn analogue of chlorapatite known so far from only two occurrences in the world, i.e., granitic pegmatites at Cross Lake, Manitoba, Canada and Szklary, Sudetes, SW Poland. In this study, we present the data on the compositional variation and microtextural relationships of various apatites highly enriched in Mn and Cl from Szklary, with the main focus on compositions approaching or attaining the stoichiometry of pieczkaite (pieczkaite-like apatites).