Linked from
The 15 pages that link to Pyrite, each with the reason it gives.
ChalcopyriteCompared with: Pyrite resembles chalcopyrite but lacks copper and is generally harder.
ArsenopyriteCompared with: Pyrite is a common associated mineral but lacks arsenopyrite's arsenic.
BorniteCompared with: Pyrite lacks copper and is harder and paler than bornite.
TroiliteCompared with: Pyrite has twice as much sulfur per iron atom as troilite.