On the ground surface, the blade of a robust and compact ax, made of green diorite was found. This hard and dark rock was buffed until it had a curved edge and shiny. In Castulo, these axes can be dated back to the Bronze Age and Copper (III and II millennium B.C.).
It was obtained from a particularly hard stone, and we can imagine a patient abrasion work until it had a symmetrical and solid piece with a carefully polished surface. This knowledge appear in the Neolithic and last until the end of the Bronze Age.