Gold-bearing veins may be eroded by a river, causing gold dust to enter the water and wash up on its banks. People use flat pans to collect the silty deposits from a river and analyse them for gold dust. According to the Gold Fever Prospecting website, between 95 and 98 per cent of the world's native gold is in the form of gold dust rather than nuggets.
Use a green, red or blue pan to collect gold dust. These colours will make it easier to spot the flash of any gold particles.
Gently shake the gold dust in the pan. If it remains relatively stationary compared to other materials then this suggests that it is heavy, like gold.
Poke the gold with a pin. If the pin bends or breaks then the substance isn't gold. In its pure form, the metal is very soft and can be easily compressed.
Expose the gold dust to sunlight. Pyrite is a yellowish metallic mineral that is often mistaken for gold, earning it the nickname, "fool's gold." Pyrite glitters in the sunlight, while gold does not.
Move a magnet across the surface of the gold dust. Any material that adheres to the magnet is not gold. Pyrite is an iron sulphide and therefore magnetic.
Don rubber gloves and protective eyewear and place the gold dust in nitric acid. Gold will remain unaffected by the acid whereas other metals will react with it.
Things you need
- Nitric acid
- Rubber gloves
- Protective goggles