About: http://webisa.webdatacommons.org/149303220

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	Under the microscope, they are shown to be made up of two kinds of materials, a base or ground-mass of a glassy character, and distinct crystals irregularly distributed through this glassy base, like the raisins in a cake.
http://www.w3.org/ns/prov#wasQuotedFrom	wikisource.org