A previous article relating to a series of outcrops of an Oligocene sandstone (Macigno) located in Tuscany along a N-NW S-SE band, illustrated that the compression strength values measu-red with the Schmidt Hammer gradually decreased from north to south. This study applies the same criteria and methods to the outcrops of another sandstone (Pietraforte = Strong Stone) belonging to the geological formation of the Super Gruppo della Calvana from the Cretace-ous-Eocene age. The results reveal a similar trend for the outcrops between Poppi (lat. 43°45’)...