blue stone vs copper sulphate

blue stone and copper sulphate both are nouns.

Word	Noun	Adjective	Verb	Adverb
blue stone	Yes	No	No	No
copper sulphate	Yes	No	No	No

As nouns, copper sulphate is a hypernym of blue stone; that is, copper sulphate is a word with a broader meaning than blue stone:

blue stone: hydrated blue crystalline form of copper sulfate
copper sulphate: a copper salt made by the action of sulfuric acid on copper oxide

Other hypernyms of blue stone include copper sulfate, cupric sulfate, cupric sulphate.

blue stone (noun)	copper sulphate (noun)
hydrated blue crystalline form of copper sulfate	a copper salt made by the action of sulfuric acid on copper oxide