Sorry but what you have is not gold, gold cannot be broken up into pieces because it is a very malleable metal, gold will only indent when poked with a sharp object and flatten out when hit with hammer, gold also will not change it appearance when in bright light and then shaded, gold has it's on glow and will appear much the same color in most all lighting conditions.
From looking at your picture what appears to look like "gold" in most likely pyrite, chalcopyrite, and or mica, basically "Fools Gold".
If you were to crush up all of that material and pan it out their could be a small amount of gold in the pyrite if that is what you have, but also there could be no gold at all.