## 1 Introduction  
Critical raw materials (CRM) are integral components of a resilient and sustainable economy and society [1, 2]. The 2020 European Union CRM list comprises the metals: Be, Bi, Co, Ga, Ge, Hf, In, Li, Nb, Sb, Sc, Sr, Ta, Ti, V, and W, as well as the group of rare earth elements (REE) and platinum group elements (PGE) [3]. A sustainable supply of mineral raw materials needs accessible deposits and efficiently productive mines [4]. Advances in ore exploration further contribute to achieving this supply chain. Alkaline- to peralkaline-carboinite igneous rocks, sedimentary uranium and phosphorrite ores, and placer-type REE deposits are the main sources for critical and rare metals [5, 6, 7]. The exploitation of critical and rare metals mainly as by-products from porphyry-epithermal systems could support this effort [8, 9]. Porphyry Cu-Au-Mo deposits are potential exploration and exploitation targets for critical and rare metals, as they exhibit enrichments in Re, Te, Co, Bi, U, and PGE [10]. The polymetallic assemblages found in the periphery of porphyry systems related to skarn, replacement, vein, and intermediate sulfidation epithermal mineralization types are enriched in Mn, Ge, Ga, In, Bi, Sb, As, W, and Te [10]. In addition, low- to high-sulfidation epithermal overprints of porphyry systems may include Te, Bi, As, Sb, V, and F [10; 11]. However, the enrichment processes of these metals and their distribution require further investigation. Bulk geochemistry and mineral chemistry of hydrothermal alterations and ore mineralization can assist in this effort. In addition, the metallic minerals hosted in porphyry-epithermal deposits could be associated with varying amounts of critical and rare metals incorporated as: (1) solid solution or nanoparticles in the crystal lattice, (2) nano-scale mineral inclusions, and (3) visible micro- to macro-scale minerals [12; 13; 14; 15; 16]. These inclusions can be formed through direct precipitation from multi-stage hydrothermal fluids into the minerals, or from processes, such as overgrowth and recrystallization, leading to exsolution, remobilization, and resorption of trace elements [12; 14]. Antimony is a CRM and is fundamental to the aerospace-defense, textiles, mobility-automotive, and construction industrial ecosystems, as it is used in defense applications (e.g., ammunition, optics, laser sighting), flame retardants, and lead-acid batteries [3]. Stibnite (Sb\({}_{2}\)S\({}_{3}\)) commonly occurs in magmatic-hydrothermal mineralization and is the principal ore mineral in Sb deposits [17; 18]. Major stibnite ores are found in the Xiangzhong metallogenic province in China (>50% of global Sb production and reserves) [16]. They include structurally controlled vein-style mineralization related to distal intrusions, which are hosted in sedimentary or metamorphic rocks [16]. Additionally, antimony and stibnite are also accommodated in epithermal vein-type mineralization and in sediment-hosted distal-disseminated mineralization found in the periphery of porphyry systems [10; 19]. Trace elemental composition of stibnite remains largely unexplored [16]. Copper, Pb, and As are the main lattice bound substitutions for Sb in stibnite (in wt.% level), whereas Au, Ag, Bi, In, Mo, Sn, Co, Cr, V, Zn, Ni, Ga, Ge, Rb, Sr, Pd, Cd, and U can be incorporated in minor amounts (ppm level), related to nano-scale mineral inclusions [16]. These inclusions comprise a range of low temperature sulfides, sulfosalts, and arsenides (e.g., marcasite, chalcopyrite, lollingite, berthierite, galena) [20]. Stibnite may also be enriched in REEs, especially in light REEs, such as Ce and La [21]. Europe has a long history in mineral raw materials exploitation. However, the European Union (EU) largely relies on imports of CRM [12]. Despite their high potential, large areas of Europe, including northern Greece, remain underexplored for ore deposits using modern exploration methods [22; 23; 24].