curio vs rarity

curio and rarity both are nouns.

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

As nouns, curio and rarity are synonyms defined as:

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

curio (noun)	rarity (noun)
something unusual -- perhaps worthy of collecting	something unusual -- perhaps worthy of collecting
	a rarified quality
	noteworthy scarcity