About: http://webisa.webdatacommons.org/446391369

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	Mafic rocks such as basalts (like those produced on Mauna Loa), gabbro (an intrusive igneous or plutonic rock), and other dark-colored low-silica rocks will erode down to components that are also dark.
http://www.w3.org/ns/prov#wasQuotedFrom	usgs.gov