Gold             v.           Iron Pyrite

Many people confuse Iron Pyrite with Gold. Here is the difference between the two.

~ Gold ~
Gold is not shiny, it does not reflect in the sunlight. It is gold in color, and dull.
Gold is heavy, when panning, it will stay at the bottom of the pan and will not float.

~ Iron Pyrite ~
Pyrite is not gold color. It is bright, shiny, and yellow color. Pyrite is not heavy.
When panning, it moves easily the same as dirt.

A good test to try

Hit it with a hammer, pyrite will shatter like glass (don't ruin a good nugget)
Or you can scrap it with your pocketknife, if it's gold, it will scratch, if it's pyrite, it will flake off.