chrysoberyl vs opaque gem

chrysoberyl and opaque gem both are nouns.

Word	Noun	Adjective	Verb	Adverb
chrysoberyl	Yes	No	No	No
opaque gem	Yes	No	No	No

As nouns, opaque gem is a hypernym of chrysoberyl; that is, opaque gem is a word with a broader meaning than chrysoberyl:

chrysoberyl: a rare hard yellow green mineral consisting of beryllium aluminate in crystal form; used as a gemstone
opaque gem: a gemstone that is opaque

Other hypernyms of chrysoberyl include mineral.

chrysoberyl (noun)	opaque gem (noun)
a rare hard yellow green mineral consisting of beryllium aluminate in crystal form; used as a gemstone	a gemstone that is opaque