Assertion: aluminum | /r/HasProperty | precious metal
Facets:
value: historically
type: TEMPORAL
value: because of the complexities
type: CAUSE
value: through most of the 19th century
type: TEMPORAL
Source sentences:
text: At that time, aluminum was only available in very small quantities, so it was a precious metal more valuable than gold or silver.
text: Because of the complexities of refining aluminum from ore, aluminum was considered more rare and precious than gold or silver through most of the 19th century.
text: Historically, aluminum was once considered a precious metal.
text: Aluminium was once considered a precious metal that was even more valuable than gold.