blue copperas vs blue vitriol

blue copperas and blue vitriol both are nouns.

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

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

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

Other synonyms of blue copperas include blue stone, chalcanthite.

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