About: http://webisa.webdatacommons.org/38412887

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	These can include: copper, selenium, nickel or other metals that serve as accelerators or reaction modifiers in the blackening solutions.
http://www.w3.org/ns/prov#wasQuotedFrom	mmsonline.com