sulphide vs pyrites

sulphide and pyrites both are nouns.

Word	Noun	Adjective	Verb	Adverb
sulphide	Yes	No	No	No
pyrites	Yes	No	No	No

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

sulphide: a compound of sulphur and some other element that is more electropositive
pyrites: any of various metallic-looking sulfides (of which pyrite is the commonest)

Other hyponyms of sulphide include hydrogen sulfide, iron disulfide, cadmium sulfide, zinc sulfide, zinc sulphide.

sulphide (noun)	pyrites (noun)
a compound of sulphur and some other element that is more electropositive	any of various metallic-looking sulfides (of which pyrite is the commonest)