Group of prismatic baryte crystals, doubly terminated and well defined, with good luster and transparency. They are disposed very aerially on the matrix. The history of the Silius mines begins in the first decades of the 20th century, particularly in 1916, when the first research permits were registered for the galena. It was in the early 1950s that the focus was on major fluorite outcrops and in 1953 the first company to obtain the mining concession for the exploitation of the rich fluors of fluorite and galena was created, the Mineraria Silius SpA, active until 2006.