blue stone vs blue copperas

blue stone and blue copperas both are nouns.

Word	Noun	Adjective	Verb	Adverb
blue stone	Yes	No	No	No
blue copperas	Yes	No	No	No

As nouns, blue stone and blue copperas are synonyms defined as:

blue stone and blue copperas: hydrated blue crystalline form of copper sulfate

Other synonyms of blue stone include blue vitriol, chalcanthite.

blue stone (noun)	blue copperas (noun)
hydrated blue crystalline form of copper sulfate	hydrated blue crystalline form of copper sulfate