About: http://webisa.webdatacommons.org/99007941

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	Though obsidian is usually dark in color similar to mafic rocks such as basalt, obsidian's composition is extremely felsic.
http://www.w3.org/ns/prov#wasQuotedFrom	wikipedia.org