About: http://webisa.webdatacommons.org/184570834

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	Crystals, such as calcite and quartz, are said to be birefringent, meaning two indices of refraction.
http://www.w3.org/ns/prov#wasQuotedFrom	arborsci.com