uncommon vs commonness

uncommon is not a noun while commonness is a noun.

Word	Noun	Adjective	Verb	Adverb
uncommon	No	Yes	No	No
commonness	Yes	No	No	No

uncommon (noun)	commonness (noun)
	ordinariness as a consequence of being frequent and commonplace
	sharing of common attributes
	the quality of lacking taste and refinement
	the state of being that is commonly observed

uncommon (adjective)	commonness (adjective)
not common or ordinarily encountered; unusually great in amount or remarkable in character or kind
marked by an uncommon quality; especially superlative or extreme of its kind