firmness vs granite

firmness and granite both are nouns.

Word	Noun	Adjective	Verb	Adverb
firmness	Yes	No	No	No
granite	Yes	No	No	No

As nouns, granite is a hyponym of firmness; that is, granite is a word with a more specific, narrower meaning than firmness:

firmness: the quality of being steady or securely and immovably fixed in place
granite: something having the quality of granite (unyielding firmness)

Other hyponyms of firmness include sureness, stability, stableness.

firmness (noun)	granite (noun)
the quality of being steady or securely and immovably fixed in place	something having the quality of granite (unyielding firmness)
the trait of being resolute	plutonic igneous rock having visibly crystalline texture; generally composed of feldspar and mica and quartz
the property of being unyielding to the touch
the muscle tone of healthy tissue