How to Test a Rock for Gold | Sciencing
Iron pyrite is attracted to magnets, but real gold is not magnetic. Real gold also leaves a gold streak when scratched against a small bit of unglazed ceramic, like the back of a piece of bathroom tile, but iron pyrite leaves a greenishblack colored streak. In your gold hunting kit, a small magnet, piece of glass and a bit of unglazed tile can help you identify real gold in a flash.