New mineralogical and geochemical data on a potential critical raw materials occurrence at Polski Gradets (Southеastern Bulgaria)

New mineralogical and geochemical data on wolframite, garnets, and scheelite (± molybdenite) in hydrothermal quartz veins and skarns from the area of the Polski Gradets ore occurrence (SE Bulgaria) are present. Wolframite is the main ore mineral partly replaced by irregular scheelite aggregates. It is mostly ferberite in composition and contains 57.47 to 72.63 mol% FeO, 22.11 to 39.01 mol% MnO and MgO from 3.52 to 6.29 mol%. The trace element concentration in the wolframites is dominated by Mo, Nb, and Cu. The studied garnets are grossular-andradites (Grs: 47.51 to 86.87 mol%; Adr: 0.00 to 52.49 mol%) enriched in V, Cr, and As.