Health & Environmental Research Online (HERO)


Print Feedback Export to File
7462714 
Journal Article 
Potassian hastingsite and potassichastingsite from garnet - hedenbergite skarn at Vlastejovice, Czech Republic 
Zacek, V 
2007 
1 
Neues Jahrbuch fuer Mineralogie. Abhandlungen
ISSN: 0077-7757 
E SCHWEIZERBARTSCHE VERLAGS 
STUTTGART 
184 
2 
161-168 
English 
WOS:000250952600004 
Potassichastingsite (3.05 wt. % K2O) occurs along with K-rich hastingsite (similar to 2.10 wt. % K2O) as large phenocrysts in metasomatic rims of pegmatite dykes penetrating Ca-Fe skarn at Vlastejovice, in the Variscan amphibolite - facies terrain of the Moldanubian Zone, Bohemian Massif, Czech Republic. The skarn is characterized by the high f (O-2) assemblage of grossularite- andradite garnet, Fe3+- enriched hedenbergite, magnetite, and epidote. Amphibole is characterized by Fe3+> Al-VI (Fe3+ 0.80 to 1.07 apfu, Al-VI 0.30 to 0.38 apfu), high X-Fe (0.83 to 0.72) and low X-site vacancies (0.09 to 0.22). The concentrations of Li, Sr, Rb and Ba are non-essential, and other trace element contents are generally low. Due to the high K content (up to 0.62 apfu) it corresponds to potassichastingsite or potassian hastingsite. The OH content ranges from 1.60 to 1.82 apfu, F from 0.17 to 0.33 apfu, but Cl only from 0.03 to 0.06 apfu. Thus this amphibole belongs to most K-rich chlorine-poor hastingsites reported: (K0.62Na0.28)(0.87) (Ca-1.95 Na-0.05)(2.00) (Fe2.792+Mg0.92Mn0.03Fe0.803+Ti0.05Al0.38)(8.00) (Si-5.Al-98(2.02))(8.00) O-22.05(OH1.71F0.18Cl0.06)(1.95). 
potassichastingsite; skarn; Vlastejovice; Bohemian Massif; Czech Republic