collectable vs curio

collectable and curio both are nouns.

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

As nouns, curio is a hypernym of collectable; that is, curio is a word with a broader meaning than collectable:

collectable: things considered to be worth collecting (not necessarily valuable or antique)
curio: something unusual -- perhaps worthy of collecting

Other hypernyms of collectable include curiosity, oddity, oddment, peculiarity, rarity.

collectable (noun)	curio (noun)
things considered to be worth collecting (not necessarily valuable or antique)	something unusual -- perhaps worthy of collecting

collectable (adjective)	curio (adjective)
subject to or requiring payment especially as specified