Sulphur is present in nature as a native element and it’s indicated with the symbol S. It belongs to the group VI of the periodic table, its atomic number is 16 and its atomic weight is 32,06. It’s not a metal, it doesn’t conduct neither heat nor electricity, it’s inflammable and very reactive, it can be combined really easily in order to form compounds. At the elementary state it’s a solid substance, tender (hardness 2 in the Mohs scale), its characteristic yellow color is often associated to the particular smell of rotten eggs caused by the presence of sulphuretted hydrogen (H_2 S). The sulphur of Perticara is characterized by a copious contamination of bitumen. Sulphur generally crystallizes in two polymorphic steps: phase α and phase β.

The sulphur that is present in the ore body of Perticara belongs to the phase α, that’s why it consists of eight-atomic cyclic molecules (S_8); crystals have the characteristic pyramidal range and the melting point is about 112,6 °. On the other hand, the sulphur β has a monoclinic structure with tubular crystals with an oblong shape and it melts at the temperature of 114°