5 (five) is a number, numeral and digit. It is the natural number, and cardinal number, following 4 and preceding 6, and is a prime number.
Humans, and many other animals, have 5 digits on their limbs.
Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock containing 25% to 75% ash is described as tuffaceous (for example, tuffaceous sandstone). A pyroclastic rock containing 25–75% volcanic bombs or volcanic blocks is called tuff breccia. Tuff composed of sandy volcanic material can be referred to as volcanic sandstone.
Tuff is a relatively soft rock, so it has been used for construction since ancient times. Because it is common in Italy, the Romans used it often for construction. The Rapa Nui people used it to make most of the moai statues on Easter Island.
Tuff can be classified as either igneous or sedimentary rock. It is usually studied in the context of igneous petrology, although it is sometimes described using sedimentological terms.
Tuff is often erroneously called tufa in guidebooks and in television programs but tufa is a form of travertine.
by Rolls
Took a chance buying this for flattening out ground before seeding grass. The assembly was fairly easy. Hooked up and worked like a dream! Didn’t even have to put blocks on top. Great piece of equipment. Ordered this because it resembled an old quack grass drag back home on the farm.