oddity vs rarity

oddity and rarity both are nouns.

Word	Noun	Adjective	Verb	Adverb
oddity	Yes	No	No	No
rarity	Yes	No	No	No

As nouns, oddity and rarity are synonyms defined as:

Other synonyms of oddity include curio, curiosity, oddment, peculiarity.

oddity (noun)	rarity (noun)
something unusual -- perhaps worthy of collecting	something unusual -- perhaps worthy of collecting
a strange attitude or habit	a rarified quality
eccentricity that is not easily explained	noteworthy scarcity