Answer
There are several ways to determine whether the nugget is fool's gold or real gold. You could
-see if its magnetic
-dissolve in acid
-determine density
Work Step by Step
Magnetism-gold is not magnetic, while fool's gold, which contains iron, is magnetic
Acid-dissolving fools gold and real gold will produce different results, which could help distinguish between the two
density-pyrite and gold have different densities, finding the density will determine what the substance is.