A vocabulary of landscape — a landscape of words
1083 entries
tufa
Tufa is a porous limestone deposited from cool fresh water, usually where a spring rich in dissolved calcium meets air or alkaline lake water and the mineral comes out of solution. It builds fast, encrusts whatever it forms around, and often preserves moss, leaves, and twigs inside it. The spires and towers standing in and around Mono Lake in California are tufa built underwater and then exposed as the lake fell.
Etymology
The word came into English from Italian, from a Latin term for a soft porous rock. It is constantly confused with tuff, which came into English from the same Latin word but means something else entirely: consolidated volcanic ash. One is deposited by water and one is erupted.
Notes
The related term travertine names the same chemistry deposited from hot water rather than cool, which produces a denser banded stone that takes a polish and has been quarried for building since Roman times. Tufa is soft, light, and full of holes, and it was used in Roman construction for exactly those properties, particularly in vaults where the weight mattered.