The interesting thing about
gold chalcogenides is the reversal in stability going from
O to
S to
Se to
Te. For gold the tellurides are the most stable (even as minerals), the sulfide and oxide are
metastable. For most other metals it is the other way around.
AuTe
2 is present as a number of
minerals, the most common being
calaverite[?].
Calaverite[?] is the most important source of gold after native gold]].
AuSe exists in two forms, AuSe and Au
2Se
3.
Au
2S is metastable, but mixed silver-gold sulfides like
AgAuS do exist.
No studies of gold polonides have been conducted yet, as polonium is very rare in nature.