7I have described the different species of lime and sand, and their qualities. Stone quarries, from which square and rubble stones are procured and prepared for the purposes of building, will now be considered. The qualities of these differ very much. Some stone is soft; the red, for instance, found in the neighbourhood of Rome, in the countries of the Pallienses, Fidenates, and Albanæ. Some moderately so, as the Tiburtine, Amiternine, Soractine, and those of that sort. Others are hard, even as flints. There are many other species, as the red and black sandstone (tophus) of Campania, and the white sort of Umbria, Picenum, and Venice, which is cut with a saw like wood.
7I have now spoken of lime and sand, with their varieties and points of excellence. Next comes the consideration of stone-quarries from which dimension stone and supplies of rubble to be used in building are taken and brought together. The stone in quarries is found to be of different and unlike qualities. In some it is soft: for example, in the environs of the city at the quarries of Grotta Rossa, Palla, Fidenae, and of the Alban hills; in others, it is medium, as at Tivoli, at Amiternum, or Mt. Soracte, and in quarries of this sort; in still others it is hard, as in lava quarries. There are also numerous other kinds: for instance, in Campania, red and black tufas; in Umbria, Picenum, and Venetia, white tufa which can be cut with a toothed saw, like wood.