Assertion: slate | /r/HasProperty | illite
Facets:
value: mainly
type: DEGREE
value: along with biotite
type: OTHER
Source sentences:
text: Slate is mainly composed of the minerals quartz and muscovite or illite, often along with biotite, chlorite, hematite, and pyrite and, less frequently apatite, graphite, kaolinite, magnetite, tourmaline, or zircon as well as feldspar.