Assertion: carbon | /r/HasProperty | made around roman times
Facets:
value: by heating wood
type: MANNER
value: by the same chemistry
type: OTHER
Source sentences:
text: Diamonds were known probably as early as 2500 BCE in China, while carbon in the form of charcoal was made around Roman times by the same chemistry as it is today, by heating wood in a pyramid covered with clay to exclude air.