curiousness vs curiosity

curiousness and curiosity both are nouns.

Word	Noun	Adjective	Verb	Adverb
curiousness	Yes	No	No	No
curiosity	Yes	No	No	No

As nouns, curiosity is a hypernym of curiousness; that is, curiosity is a word with a broader meaning than curiousness:

Other hypernyms of curiousness include wonder.

curiousness (noun)	curiosity (noun)
the quality of being alien or not native	something unusual -- perhaps worthy of collecting
a state of active curiosity	a state in which you want to learn more about something