Assertion: cassiterite | /r/HasProperty | black
Facets:
value: usually
type: DEGREE
Source sentences:
text: Cassiterite is usually black or generally dark in color, and these deposits can be easily seen in river banks.
text: Cassiterite is one of those black rocks that gets a lot of attention due to the fact that it is found in a lot of world localities, and in some cases, the crystals are truly superb.