Mexican onyx vs calcite

Mexican onyx and calcite both are nouns.

Word	Noun	Adjective	Verb	Adverb
Mexican onyx	Yes	No	No	No
calcite	Yes	No	No	No

As nouns, calcite is a hypernym of Mexican onyx; that is, calcite is a word with a broader meaning than Mexican onyx:

Mexican onyx: a hard compact kind of calcite
calcite: a common mineral consisting of crystallized calcium carbonate; a major constituent of limestone

Mexican onyx (noun)	calcite (noun)
a hard compact kind of calcite	a common mineral consisting of crystallized calcium carbonate; a major constituent of limestone