Assertion: graphite | /r/Synonym | black lead
Facets:
value: because of its metallic appearance
type: CAUSE
value: historically
type: TEMPORAL
Source sentences:
text: Historically, graphite was called black lead or plumbago.
text: For example, graphite is opaque and black while diamond is highly transparent.
text: A special environment is necessary for Graphite (black carbon) to change into Diamond (white carbon).
text: Graphite is a stable form of naturally occurring carbon, also known as plumbago, blacklead or mineral carbon.
text: Graphite is also known as black lead or plumbago.
text: The name originated in Europe when graphite was called “plumbago” or “black lead” because of its metallic appearance.
text: They are made with graphite, which is also called black lead or plumbago, mixed with clay.