Diamond can be Clear. Diamond is the opposite of Coal. 
Host is a type of Patron. Host is a type of Book. Pen is the Book. you are likely to find Pen in/at/on Classroom. 
Clear <--HasProperty-- Diamond <--Antonym--> Coal 
Patron <--IsA-- Host --IsA--> Book <--DefinedAs-- Pen --AtLocation--> Classroom 