Piran Sel Gris is unrefined and rich in marine minerals. Its trademark sweet-mineral taste is due to the unique properties of the Adriatic aquamadre (the dense liquid that results from the natural production of marine salt from sea water), captured in the shining crystals. This salt is prized for its abundant of microelements, which are said to form in the petola, a foundation of biosediment, on the bottom of the crystallization pans.