Looks like Biotite Mica to me but...
>Take a needle or stick pin and poke it. If it breaks it's not gold, if it dents it could be gold. You can also hit it with a hammer if you don't care what shape it ends up in. Gold will flatten, most everything else with flake, crush, or crumble
>Next (or maybe first depending on the hammer scenario) get yourself a piece of porcelin or a chunk of tile, rub it across the unglazed side and tell us what color it is. Gold- yellow streak, Pyrite- greenish black, Mica - white or no streak.
>Gold shines but doesn't sparkle like glitter, hold it in the light and notice the shine, turn it in the light the shine shouldn't change, now shade it with your hand it should look the same
>Gold usually looks worn, rounded, or irregular. Mica and pyrite tend to be angular, sharper crystal type structures