Nenfro is a volcanic rock, gray tuff or banded trachyte (Brocchi) or leucite phonolite lava (Rosenbusch) with a soft but compact structure, [1] typical of the Viterbo region that the Etruscans used in their sculptures of northern Lazio Cimini hills near Rome, Italy. [2]
One of its features is to take a pinkish tint when drying. [4]