aloneness vs solitariness

aloneness and solitariness both are nouns.

Word	Noun	Adjective	Verb	Adverb
aloneness	Yes	No	No	No
solitariness	Yes	No	No	No

As nouns, aloneness and solitariness are synonyms defined as:

Other synonyms of aloneness include loneliness, lonesomeness.

aloneness (noun)	solitariness (noun)
a disposition toward being alone	a disposition toward being alone
	the state of being alone in solitary isolation