Travertine

A terrestrial sedimentary rock, formed by the precipitation of carbonate minerals from solution in ground and surface waters, and/or geothermally heated hot-springs

 

Pozzolana

Finely divided siliceous or siliceous and aluminous material that reacts chemically with slaked lime at ordinary temperature and in the presence of moisture to form a strong slow-hardening cement, aka volcanic Italian sand

 

Roman concrete

Concrete made by the Romans using pozzolana instead of other sands

 

Voussoir

Wedge-shaped block (typically of a durable stone) used to make a true arch

 

Curia

In ancient Rome, one of the original groupings of citizens, eventually numbering 30, and later every Roman citizen was presumed to belong to one