What was the name of the volcanic stone native to italy used by the romans before concrete was used on the building scene?

The name of the volcanic stone was tufa and travertine. It was a native stone to Italy and was used by the Romans before using concrete for buildings. This was used in order to make the buildings looked like Greek marble. it was dedicated to God Portunus who was a divine that was associated with keys, harbors, and livestock. It also gave a topographical position of the buildings which were located near the ancient river of Harbor City of Rome.

the completion of the erie canal spurred the first great westward movement of american settlers, gave access to the rich land and resources west of the appalachians and made new york the preeminent commercial city in the united states.

the conditions that made the byzantine empire vulnerable to attacks by the muslin turks were the sack of constantinople by western crusaders, the conquests of the sultanate of rum, presence of rival kingdoms and finally the set up of fiefdoms at the empire which were owned by the ghazis (turkish warriors).