About: http://webisa.webdatacommons.org/211318691

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	These are found in volcanic flows or as dikes with large crystals (called phenocrysts), up to centimeters long of a single mineral set in a very fine-grained matrix of the same or other minerals.
http://www.w3.org/ns/prov#wasQuotedFrom	ncse.com