The famous Trepča / Stari Trg mine is located in the area of the Kopaonik mountain, about 10 km northeast of the Kosovo city of Mitrovica, on the eastern side of the Ibar river valley. It is a lead-zinc ore deposit with the main ore minerals GALENA and SPHALERITE, and mineralization occurs in the form of skarn, hydrothermal-metasomatic and vein mineralization. The skarn paragenesis is characterized by ilvaite-hedenbergite-actinolite and andradite-magnetite skarn with some epidote with carbonates and quartz. Hydrothermal paragenesis is the most represented mineral paragenesis both in terms of the amount of deposited ore and in terms of the amount and beauty of crystal clusters. It also made the name of Trepča and Stari Trg famous in the world.

In addition to being exceptionally beautiful, such druses are ideal for studying paragenetic relationships and crystallization processes. Numerous studies have been conducted on them so far, including goniometric measurements of crystals, determination of morphology, and parallel perspective drawings of single and twinned crystals. Numerous pseudomorphoses have been defined and oriented intergrowths of various minerals, and the chemical and phase composition and structure, especially of sulfide and carbonate minerals, have been determined.

The special value of the Trepča / Stari Trg Collection is also reflected in its historical development. Namely, the collection dates back to the first visits of mineralogy professor Fran Tućan to the mine in 1925 in order to provide an expert opinion on possible ore reserves and prospects for more serious exploitation, until the beginning of the conflict in Kosovo and the cessation of mine operations.