An ancient building material, gypsum is now irreplaceable. Its quality is essential to ensure the best performance applied to building systems. This is why the company has invested heavily in gypsum quarries, acquiring experience both in opencast quarrying and underground mining. The latter in particular best represent Fassa’s constant commitment to pursuing technical solutions and quarrying methods that enable rational exploitation of mineral deposits with limited impact on the surrounding environment. Fassa’s first underground gypsum mine started operating in 1993, in Moncalvo (Asti). This experience was then consolidated and extended to other underground operations, again in Asti province. The gypsum deposits in the Monferrato area of Piedmont are generally high quality, and underground mining allows the best parts to be reached, favouring extraction of the mineral gypsum without contamination by clay, marl or altered gypsum, as often occurs in opencast quarries.

Several underground mining methods are used, including:
- Room and pillar method;
- Room and diaphragm method.
The method used by Fassa for quarrying gypsum is mainly room and diaphragm, which involves creating chambers or rooms separated by rock diaphragms. The rooms are actually tunnels that can be created using explosives or by mechanical excavation (e.g. borers). This type of mining allows only limited exploitation of the reserves, yet ensures a high level of stability for the rooms at the end of operations, as well as assisting the extraction of dust during mining and therefore guaranteeing healthier underground working conditions, as the work environment remains confined to the front of the tunnel. The use of innovative technology in the sector, i.e. mechanical boring with roadheaders, allows a higher level of mechanisation of the mining operations: this means high productivity, safety for personnel and, above all, a negligible visual impact.