A quern is an object made of hard stone used to grind grain into flour. A rough but hard stone was necessary, to avoid grit in the flour. Lava was widely traded for the purpose. Querns have been used since the Neolithic period and are still used in some parts of the world today. Some querns, the beehive and rotary types, require the grain to be placed between two stones, the overlying stone is then hand rotated over the underlying stone. Beehive querns have been found at two Iron Age hillforts in Surrey at Hascombe Camp, Hascombe and Holmbury Camp, Shere.
Another type of quern is the saddle quern, which consists of a large underlying stone with a depression in the top that the grain was put into, and a smaller (rubbing) stone which was then pushed back and forth over the stone to grind it. A Bronze Age or Early Iron Age saddle quern was found in a field in Leatherhead in 1948.
Sometimes unfinished querns are found in archaeological contexts. These are known as quern roughouts.
Finding querns in an archaeological site, especially prehistoric sites, is very useful for identifying what that site was used for, as a quern is a good indicator of domestic settlement, and that the site was probably used for habitation.