uniqueness vs unique

uniqueness is a noun but unique is not a noun.

Word	Noun	Adjective	Verb	Adverb
uniqueness	Yes	No	No	No
unique	No	Yes	No	No

uniqueness (noun)	unique (noun)
the quality of being one of a kind

uniqueness (adjective)	unique (adjective)
	radically distinctive and without equal
	the single one of its kind
	(followed by `to') applying exclusively to a given category or condition or locality
	highly unusual or rare but not the single instance