PropertyValue
http://www.w3.org/1999/02/22-rdf-syntax-ns#type
http://www.w3.org/ns/prov#value
  • These ancient stars formed from pristine gas that was ???uncontaminated??? by heavy elements, such as carbon, oxygen or silicon, into it.
http://www.w3.org/ns/prov#wasQuotedFrom
  • nasa.gov