About: http://webisa.webdatacommons.org/23558699

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	Other elements such as copper and iron contribute to the tarnish by producing their black sulphide compounds5and by electrochemical behaviour6.
http://www.w3.org/ns/prov#wasQuotedFrom	vam.ac.uk