About: http://webisa.webdatacommons.org/343131450

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	nderground mines for the purposes of exploration, or extraction of nonmetallic minerals, metallic ores, coal, and building materials such as stone and gravel, whether paid on a time, piece rate, commission, or other basis, except that:
http://www.w3.org/ns/prov#wasQuotedFrom	ca.gov