identicalness vs identical

identicalness is a noun but identical is not a noun.

Word	Noun	Adjective	Verb	Adverb
identicalness	Yes	No	No	No
identical	No	Yes	No	No

identicalness (noun)	identical (noun)
exact sameness

identicalness (adjective)	identical (adjective)
	(of twins) derived from a single egg or ovum
	coinciding exactly when superimposed
	having properties with uniform values along all axes
	exactly alike; incapable of being perceived as different
	being the exact same one; not any other: