pegmatite vs igneous rock

pegmatite and igneous rock both are nouns.

Word	Noun	Adjective	Verb	Adverb
pegmatite	Yes	No	No	No
igneous rock	Yes	No	No	No

As nouns, igneous rock is a hypernym of pegmatite; that is, igneous rock is a word with a broader meaning than pegmatite:

pegmatite: a form of igneous rock consisting of extremely coarse granite resulting from the crystallization of magma rich in rare elements
igneous rock: rock formed by the solidification of molten magma

pegmatite (noun)	igneous rock (noun)
a form of igneous rock consisting of extremely coarse granite resulting from the crystallization of magma rich in rare elements	rock formed by the solidification of molten magma