Question: where is clay soil found in the world

title: Clay
text: Clay is a finely - grained natural rock or soil material that combines one or more clay minerals with possible traces of quartz ( SiO ) , metal oxides ( Al O , MgO etc . ) and organic matter . Geologic clay deposits are mostly composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure . Clays are plastic due to particle size and geometry as well as water content , and become hard , brittle and non -- plastic upon drying or firing . Depending on the soil 's content in which it is found , clay can appear in various colours from white to dull grey or brown to deep orange - red . Electron