Someone had dumped a tailings pile near the woods where I lived and in the sun, those crushed pieces of rock sparkled. I had already been bitten by the love of minerals and fossils and so naturally I filled my pockets and brought as much home as a youngster can carry.
Where I was told that it was Fool's Gold.
But, still... it was so compelling and just so gold-like. So, secretly I continued my forays and dragged as many of those lovely sparkly bits home as I could. The pile soon amassed to what could not be concealed in a youngsters room — those socks have to live somewhere. So we struck a bargain. My folks would let me keep my gold if I kept it under the house. I suspect it is still there to this day.
I did eventually find gold up in Atlin, British Columbia — and loads of it — but none that I could keep. I met a fellow who pans for it and had built out a sluicing system to great success. He showed me an ice cream bucket full of gold nuggets that I still ponder to this day.
So, what exactly is Fool's Gold? Is it gold mixed with another mineral or something else altogether? Turns out it is pyrite which has a brass-yellow colour and metallic lustre similar to gold, but pyrite is brittle and will break rather than bend as gold does.
A good field test is to give it a streak test. Gold leaves a yellow streak, while pyrite’s streak is brownish-black.
Pyrite is named from the Greek word for fire, "pyr" because pyrite can create sparks for starting a fire when struck against metal or stone — also fun to try in the field. Pyrite was once a source of sulfur and sulfuric acid, but today most sulfur is obtained as a byproduct of natural gas and crude oil processing.
We sometimes see pyrite sold as a novelty item or made into costume jewellery. But pyrite does have its uses beyond amusing youngsters dreaming of their own gold rush.
Pyrite can sometimes help you find real gold because the two form together under similar conditions. Gold can even occur as inclusions inside pyrite, sometimes in mineable quantities depending on how effectively the gold can be recovered.
Fool’s Gold is truly pyrite or iron sulfide (FeS2) and is one of the most common sulfide minerals. Sulfide minerals are a group of inorganic compounds containing sulfur and one or more elements.
I still have a fondness for it and share a wry smile when I find it out in the field. It is remarkably common. And, I do still want it to be real gold even though my grown-up brain knows it is not.
When I am very lucky, however, I find pyritized fossils — even better than gold!
