Assertion: glass | /r/MadeOf | sediment
Facets:
value: from the nile river
type: LOCATION
value: for at least 6000 years
type: TEMPORAL
Source sentences:
text: Glass has been made for at least 6000 years, since the Egyptians coated figurines made from sand (SiO 2 ) with sediment from the Nile river, heated these objects until the coating was molten, and then let them cool.