About: http://webisa.webdatacommons.org/216448477

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	When the workpiece is treated such as by peening to refine the surface grains, the resulting oxide layer may be gray in color instead of blue-black.
http://www.w3.org/ns/prov#wasQuotedFrom	google.es