Assertion: basalt | /r/HasProperty | coloured
Facets:
value: usually
type: DEGREE
Source sentences:
text: mafic rock, lesser content of silicon relative to felsic rocks, with predominance of mafic minerals pyroxenes, olivines and calcic plagioclase; these rocks (example, basalt, gabbro) are usually dark coloured, and have a higher density than felsic rocks.