About: http://webisa.webdatacommons.org/164964992

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	Obsidian, the material of which this Aztec disc is made, is a naturally occurring glass formed when felsic lava flows from a volcano and cools down without forming crystals.
http://www.w3.org/ns/prov#wasQuotedFrom	espejonegro.com