Work took place to finish the excavation, begun in 2017, of the structures of a late 18th century forge associated with a twenty-year mining concession (1784-1804) belonging to Vittorio Amedeo III and the iron and steel works of Rondolere (active 1788-1813) below. Confirming what emerged during the first campaign; the structure was enclosed in the colluvial deposits of the slope, with the foundations resting on the rocky substratum, and all floors paved with stone slabs. A substantial amount of residues of archaeo-metallurgical interest was recovered (slag, dust, rust, incrustations, and wood charcoal – mainly beech).

A second structure, dry-stone built, came to light about two metres uphill from the forge. It was also enclosed in the hillside and occupied a surface area of 4 × 4.6 m2 and stood to 3. 5 m. This was a complex structure, consisting of an upside-down truncated cone shaped vat resting on a quadrangular platform and delimited externally by walls that followed the platform’s shape. To the south there was a stone slab floor bordered to the west by a low wall. There was a splayed quadrangular opening (0.45-0.75 m wide, 0.50 m high) in the wall on the south side of the platform. The lower part of the building was completely preserved up to the height of the architrave over the opening (found in situ), and for about 50% in the upper section. The architectural characteristics and associated materials (large quantities of mineral, gangue and iron dusts) indicate that this was a furnace for roasting the magnetite extracted from the mine situated about 20 m uphill. The find is largely a surprise. In fact, the archive documents regarding Rondolere and Pietra Bianca do not mention a roasting furnace and structures with this function were associated with hematite, for example at Brosso, in val Chiusella (Turin), but not with magnetite. The building certainly dates to the late 18th century, as attested by the associated pottery and the use in the walls of several blocks with drill holes in them (datable on a technological basis to the post mid 17th century period).

A crusher made of monzonite stone was positioned on the paving at the foot of the platform, in correspondence with the opening and held in place by a system of wedges and flanked by two sub-circular depressions. Like another in micaceous gneiss, incorporated within the platform, this crusher dates to a period pre-dating the 18th century and can be added to the five similar finds recovered from the forge collapse in 2017.

The problem remains of finding the foundations of the archaic reduction furnace, which can be associated with an enfeoffment of Emanuele Filiberto in 1570, of which substantial remains of the interior lining of heat altered clay are known, scattered on the hillside below the structures mentioned above. As things stand at present, the absence of heat altered clay on the inside walls of the roasting furnace and on the walls of the forge indicates that this material was extraneous to the operations carried out in the late 18th century structures. Bearing in mind the width and depth of the cut opened in the hillside in order to build the roasting furnace, it is becoming increasingly likely that the archaic installation was completely destroyed at the end of the 18th century.