Well, how much exactly then? Can't be much, or it surely would already have been observed decades or centuries ago. So probably not in the least commercially viable.
Regardless of it’s gold content, pyrite has commercial uses:
From WIKI:
Pyrite remains in commercial use for the production of sulfur dioxide, for use in such applications as the paper industry, and in the manufacture of sulfuric acid. Thermal decomposition of pyrite into FeS (iron(II) sulfide) and elemental sulfur starts at 540 °C (1,004 °F); at around 700 °C (1,292 °F), pS2 is about 1 atm.[17]
A newer commercial use for pyrite is as the cathode material in Energizer brand non-rechargeable lithium batteries.[18]
Pyrite is a semiconductor material with a band gap of 0.95 eV.[19] Pure pyrite is naturally n-type, in both crystal and thin-film forms, potentially due to sulfur vacancies in the pyrite crystal structure acting as n-dopants.[20]