atomic number 58 vs bastnaesite

atomic number 58 and bastnaesite both are nouns.

Word	Noun	Adjective	Verb	Adverb
atomic number 58	Yes	No	No	No
bastnaesite	Yes	No	No	No

atomic number 58 (noun)	bastnaesite (noun)
a ductile grey metallic element of the lanthanide series; used in lighter flints; the most abundant of the rare-earth group	a yellow-to-brown mineral that is a source of rare earth elements