"Iron Pyrite has so often been mistaken for gold that its better-known name is "fool's gold." It has a warm yellow color, it's metallic, and it glitters and sparkles just like the real thing. So how can you tell if you've found gold, or simply fool's gold?
- Try using a straight pin to stab the specimen. Gold is a very soft metal and will bend or break when you do this; iron pyrite is much harder and won't budge.
- If you have a 10x magnifier (or loupe), examine your find closely. Pyrite has a cubic structure; gold does not.
- Take a magnet with you. Iron pyrite will stick to the magnet because of its high iron content; gold will not.
- You can also use a drop of nitric acid to test your specimen. (Caution is advised.) Nitric acid will turn iron pyrite black, but gold will remain the same color."