Assertion: metal's ore | /r/HasProperty | sulfide
Facets:
Source sentences:
text: The concentration of copper in ores averages only 0.6%, and most commercial ores are sulfides, especially chalcopyrite (CuFeS 2 ), bornite (Cu 5 FeS 4 ) and, to a lesser extent, covellite (CuS) and chalcocite (Cu 2 S).