To better protect his baby this looks like, but really to hide the fact that it's volcanic tufa.

They seek in our islands for the earth most similar to this, and prefer a yellowish red volcanic tufa.

Where formerly sprang up that charming verdure, the soil was now nothing but a savage mass of volcanic tufa.

The country through which we were travelling was covered with a cindery-looking volcanic tufa, and might be called "Katakaumena."

It is only in some ravines, that we find columnar basalts, somewhat curved, and above them very recent breccia, resembling volcanic tufa.

Formerly a barrier of volcanic tufa stretched across the valley of the Borne; this barrier had been ejected from the volcano of La Denise.

I left Arequipa on the morning of February 9th, going through country of volcanic tufa and red sand, with immense furrows quite devoid of vegetation.

It was excavated through volcanic tufa and was 3,000 feet long, 25 feet wide, and of the pointed arch style.

Iceland, which is entirely devoid of alluvial soil, is wholly composed of volcanic tufa, that is to say, an agglomeration of porous rocks and stones.