Gold - the metal on which many empires have grown (and withered) is a strange metal indeed. In nature it occurs as a native metal, which means that it is found almost all the time as just gold and not combined with other elements to form a mineral. To ancient people this was a huge bonus, as they could find gold in rivers then use it immediately to beat into thin sheets, to make ornaments and adorn religious items. They did not need to smelt, refine or extract gold from another compound. That said, gold was and still is quite rare.
The lure of gold continues to this very day with single prospectors to very large companies looking for gold around the world. At a smaller scale, panning for gold in a river can be a load of fun especially if you can find a few flecks of 'color' to encourage your search.
Science of gold
Gold is very heavy - over 19 times weaver than water. Gold is quite soft and can be easily beaten into very thin sheets or drawn out to very thin wires. If you scratch gold, the color you get is 'gold'. Gold has no real smell when scratched either.
But not everything we find that glitters is gold. Many a novice gold seeker will come across a few minerals that glitter, but are NOT gold.
The most common mineral to fool the novice prospecter is pyrite. Aptly named 'fools gold', pyrite is quite a common mineral. It is heavy and gold-ish in color. Fresh pyrite is more of a silver-gold than true gold in color - but as it weathers it can become quite a deep golden color. All good geologists will tell you that color is really never a good way to identify minerals. But the comparisons between gold and pyrite really stop there.
Fools gold - Pyrite
Pyrite is hard and quite brittle. You will have a hard time scratching it - and when you do the powder created (geologists call it 'streak') is black. Pyrite is a compound of iron and sulfur and so the scratched or weathered surface can have a rotten-egg odor.
Knowing those few facts can make sure you don't mistake fools gold for the real thing!
However, just to prove how complex nature can be, in most of the world mined gold deposits the companies are extracting small blobs of gold that are found embedded in pyrite crystals...and so the relationship between the fools gold and real gold is a lot closer than you can imagine!