PIEMONTITE OCCURRENCE FROM THE AREA OF PETROVO VILLAGE, SOUTH PIRIN, BULGARIA

A new piemontite occurrence for Bulgaria has been recorded within the calc-silicate schists of the Orelek metamorphic complex. The rock -forming minerals of the piemontite host rocks are represented by enriched by manganese white mica, calcite, quartz, feldspar (oligoclase/albite), and sphene. The piemontite was characterized in detail by optical investigations, powder X-ray diffraction and scanning electron microscopy energy dispersive spectroscopy (SEM-EDS) and Electron microprobe analyser (EPMA). The manganese content varies in the piemontite crystals from 5.23% up to 9.75%. Field and mineralogical features indicate that this mineralization is a result of regional metamorphism of Mn-containing calcareous-pelitic protolith in the condition of greenschist to amphibolite facies.