About: http://webisa.webdatacommons.org/239221061

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	Known originally through compounds such as Epsom salts (the sulfate), magnesia (the oxide), and magnesia alba (the carbonate), the silvery white element itself does not occur free.
http://www.w3.org/ns/prov#wasQuotedFrom	britannica.com