Pulvis
puteolanus, the so called “pozzolana”, is a yellow coloured earth of
volcanic origin, still very much used in building and, together with tufa, also
erupted from the earth and widely used in the building trade, has given origin
to the activity of the extraction from the quarries of
“pozzolana” and tufa. It is for this reason that the material, used
in the construction of houses and buildings in the cities of the Neapolitan and
Phlegraean area, are dug directly from the bowels of the earth
on which they stand.
Views of the quarries of “pozzolana” – C.L. Chatelet – XV111 century