Assertion: anthracite's density | /r/HasProperty | metallic
Facets:
value: with a mildly brown reflection
type: OTHER
value: often
type: DEGREE
Source sentences:
text: Anthracite differs from ordinary bituminous coal by its greater hardness (2.75–3 on the Mohs scale), its higher relative density of 1.3–1.4, and luster, which is often semi-metallic with a mildly brown reflection.