About: http://webisa.webdatacommons.org/150196556

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	Many of the German mines of the middle ages had naturally occuring impurities of vanadium, selenium, and other elements that made the resulting products incredible.
http://www.w3.org/ns/prov#wasQuotedFrom	discovermagazine.com