Rare Occurrence of Mirabilite in the Thirteenth-Century Historic Salt Mine in Bochnia (Poland): Characterisation, Preservation, and Geotourism

In the thirteenth-century Wieliczka and Bochnia Royal Salt Mines, a rare occurrence of mirabilite (Na₂SO₄·10H₂O) and blödite (Na₂Mg(SO₄)₂·4H₂O) stalactites has been documented, attributed to contemporary precipitation from percolating solutions. This unique phenomenon is linked to a stable microclimate—low temperature, high humidity, and strong air circulation—and the chemical composition of leaking solutions, characterized by low carbonate, high sulfate content, acidic pH (4.8), and intermediate mineralization (174,308 mg/L). The study combines geological, mineralogical, and hydrochemical analyses to propose preservation strategies for these fragile minerals, which could enhance geotourism in this UNESCO World Heritage Site.

Puławska, A., Manecki, M., Flasza, M., Waluś, E., & Wojtowicz, K. (2021). Rare Occurrence of Mirabilite in the Thirteenth-Century Historic Salt Mine in Bochnia (Poland): Characterisation, Preservation, and Geotourism. Geoheritage, 13(2). https://doi.org/10.1007/s12371-021-00562-y