Assertion: aluminum | /r/HasProperty | rare
Facets:
value: in native form
type: OTHER
value: very
type: DEGREE
value: until 1886
type: TEMPORAL
Source sentences:
text: Aluminum is very rare in its free form.
text: Aluminium (or aluminum) metal is very rare in native form, and the process to refine it from ores is complex, so for most of human history it was unknown.
text: (codes: A = aluminium, C = copper, E = rare earths, usually provided by adding mischmetal to the melt, H = thorium, K = zirconium, L = lithium, M = manganese, O = silver, S = silicon, T = tin, W = yttrium, Z = zinc)
text: Tin has been in use for making jewelry and ornaments, whereas aluminum had once been considered as a rare metal, and more expensive than gold.
text: Until 1886, aluminum was rare and more valuable than gold.