Mask is related to Hide. Hide is a different concept from Reveal. Revelation is derived from Reveal. Revelation is a type of Insight. 
Dirty is related to Coal. Coal is related to Dust. Dust is related to Fine. 
Mask <--RelatedTo--> Hide <--DistinctFrom--> Reveal <--DerivedFrom-- Revelation --IsA--> Insight 
Dirty <--RelatedTo--> Coal <--RelatedTo--> Dust <--RelatedTo--> Fine 