About: http://webisa.webdatacommons.org/173467649

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	They are all calibrated ovals at 8 x 6mm and are range from mostly B to C grade opa...
http://www.w3.org/ns/prov#wasQuotedFrom	opal-trader.com