. "Dirt is unclean matter, especially when in contact with a person's clothes, skin or possessions when they are said to become dirty. Common types of dirt include: dust \u2014 a general powder of organic or mineral matter filth \u2014 foul matter such as excrement grime \u2014 a black, ingrained dust such as soot soil \u2014 the mix of clay, sand and humus which lies over the bedrock"@en . .