Fiamme are lens-shapes, usually millimetres to centimetres in size, seen on surfaces of some volcaniclastic rocks. They can occur in welded pyroclastic fall deposits and in ignimbrites, which are the deposits of pumiceous pyroclastic density currents. The name fiamme comes from the Italian word for flames, describing their shape. The term is descriptive and non-genetic. Fiamme are most typical of welded lapilli-tuffs and are commonly found in association with eutaxitic textures, best seen under the microscope.