Assertion: asteroid belt's asteroid | /r/HasProperty | up to 80% iron
Facets:
Source sentences:
text: The metallic asteroids are composed of up to 80% iron and 20% a mixture of nickel, iridium, palladium, platinum, gold, magnesium and other precious metals such as osmium, ruthenium and rhodium.
text: Metallic asteroids are composed of nearly 80% iron and 20% nickel, as well as small amounts of gold, magnesium, iridium, platinum, and several other precious metals.