Tufa belong to a group of crust-like carbonate deposits that are formed through the organically and inorganically controlled precipitation of calcium carbonates from fresh water. Other members of this group are travertines, sinters, and lacustrine limestones or marl lake deposits. Cave deposits of a somewhat similar origin are called flowstones, speleothems (stalagmites and stalactites). The terms tufa and travertine have a Latin origin. The first is derived from tophus and was used by Pliny to describe porous whitish deposits including volcanic material, which is nowadays called volcanic tuff. The term travertine stems from lapis tiburtinus or Tibur stone.

The distinction of terms used to describe surface freshwater carbonates in the literature is not very clear. However, today the term tufa is usually used to describe the more porous varieties, while travertines are denser and sometimes laminated. Sinters are mostly laminated and lack porosity. Lacustrine limestones are hardly compacted...