shininess vs refulgency

shininess and refulgency both are nouns.

Word	Noun	Adjective	Verb	Adverb
shininess	Yes	No	No	No
refulgency	Yes	No	No	No

As nouns, refulgency is a hypernym of shininess; that is, refulgency is a word with a broader meaning than shininess:

shininess: the visual property of something that shines with reflected light
refulgency: the quality of being bright and sending out rays of light

Other hypernyms of shininess include effulgence, radiance, radiancy, refulgence, shine.

shininess (noun)	refulgency (noun)
the visual property of something that shines with reflected light	the quality of being bright and sending out rays of light