immateriality vs immaterial

immateriality is a noun but immaterial is not a noun.

Word	Noun	Adjective	Verb	Adverb
immateriality	Yes	No	No	No
immaterial	No	Yes	No	No

immateriality (noun)	immaterial (noun)
the quality of not being physical; not consisting of matter
complete irrelevance requiring no further consideration

immateriality (adjective)	immaterial (adjective)
	not consisting of matter
	of no importance or relevance especially to a law case
	without material form or substance
	not pertinent to the matter under consideration
	(often followed by `to') lacking importance; not mattering one way or the other