About: http://webisa.webdatacommons.org/425423009

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Stoneware clay is often accompanied by impurities such as iron or carbon, giving it a dirty look, and its plasticity can vary widely.[3] Non-refractory fire clay may be another key raw material.
http://www.w3.org/ns/prov#wasQuotedFrom	wikipedia.org