As well as grain, ethnographic evidence and Mesopotamian texts show that a wide range of foodstuffs and inorganic materials were processed using stone querns or mortars, including nuts, seeds, fruit, vegetables, herbs, spices, meat, bark, pigments, temper and clay. Moreover, one study analysing quern-stones noted that a number of querns had traces of arsenic and bismuth, unlike their source rocks, and had levels of antimony which were ten times higher than those of the rocks. The authors concluded that this was probably due to the use of these querns in the preparation of medicines, cosmetics, dyes or even in the manufacture of alloys.