sphericalness vs sphericity

sphericalness and sphericity both are nouns.

Word	Noun	Adjective	Verb	Adverb
sphericalness	Yes	No	No	No
sphericity	Yes	No	No	No

As nouns, sphericalness and sphericity are synonyms defined as:

Other synonyms of sphericalness include globosity, globularness, rotundity, rotundness.

sphericalness (noun)	sphericity (noun)
the roundness of a 3-dimensional object	the roundness of a 3-dimensional object