If you want to extract gold within iron pyrite, there is a way to do this but it is extremely toxic. Jeff Williams has a very informative video on how to do this on YouTube. You could also try crushing the rock to see if there is any free mill gold in it.

With that much pyrite showing it is very likely to have some free milling gold,,,, crush to fine powder and gravity separate (pan it). But when gold is found associated with pyrite it is highly likely that the majority of the gold is in the sulfide form which you cannot see and cannot extract by gravity methods. It is not really feasible for must of us to undertake the chemical methods necessary to extract the gold on a small scale. You could, however, send a sample of it off for assay if you just have to know, your buddy just might want to know if he is living on top of a gold mine!