Pyrrhotite with Calcite

Unknown Owner

Help improve this recordNo owner is registered for this specimen yet. If it's yours or you know more about it, you can add the owner, provenance, publications and other details.

A pseudo-hexagonal thick crystal of pyrrhotite 1.5 cm in size on a crystallized calcite matrix with minor chalcopyrite. In good condition, neat locality example for the species. The crystal is likely in the process of being replaced by pyrite.The Osikovo deposit, accessed via the Septemvri Mine within the Madan ore field of the Smolyan province in southern Bulgaria, is situated in the central Rhodope Mountains. Its geology is defined by Paleogene hydrothermal vein and carbonate-replacement systems cutting through a metamorphic basement of Precambrian to Paleozoic gneisses, schists, and marbles. The mineralization formed from hydrothermal fluids driven by Oligocene magmatic activity, producing rich deposits of lead and zinc alongside a diverse mineralogy featuring galena, sphalerite, pyrite, quartz, and various carbonate gangue minerals. While the broader Madan region has ancient mining roots dating back to Thracian and Roman times, modern industrial underground extraction at the deposit expanded significantly during the mid-twentieth century under state-run socialist programs, continuing active operations into the modern era.