shininess vs refulgence

shininess and refulgence both are nouns.

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

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

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

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

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