sandstone vs bluestone

sandstone and bluestone both are nouns.

Word	Noun	Adjective	Verb	Adverb
sandstone	Yes	No	No	No
bluestone	Yes	No	No	No

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

sandstone: a sedimentary rock consisting of sand consolidated with some cement (clay or quartz etc.)
bluestone: bluish-grey sandstone used for paving and building

Other hyponyms of sandstone include firestone, holystone, grit, gritrock, gritstone, brownstone, greensand, siltstone.

sandstone (noun)	bluestone (noun)
a sedimentary rock consisting of sand consolidated with some cement (clay or quartz etc.)	bluish-grey sandstone used for paving and building