In his text he mentions gypsum (gypsum), mortar (maltha), limestone (calx), lime (calx viva), burnt lime (calx recens), marble (marmor), potter's clay (argilla) and the use of earthen (fictilis) pipes as water ducts.
On the other hand--again in contrast to Pliny--Isidore makes no attempt to be exhaustive; his examples of earths (taken from previous sources) are relatively few, including only potter's clay (argilla, from which "vessels--vasa--are made", i.e.