| In cool limestone regions, calcite-rich water seeps down through rocks to fill cavities with stalactites and stalagmites. Geologists have christened this phenomenon 'tufa' and it can be found near hot springs or cascades. Here it is formed by tiny particles that are carried up through the watery sprays, to become almost 'a riverfrozen in time'. Travertines are the deposits left behind. Usually of pale colour, and due to their marble-like qualities, they have been prized by sculptors for millennia. |