About: http://webisa.webdatacommons.org/350013284

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	Weighting materials include such materials as calcium carbonate, silicates, clays, and the like, but more preferably are the heavier minerals such as the barites, specular hematite, iron ores, siderite, ilmenite, galena, and the like.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com