The mineral pyrite has been historically referred to as the gold of the fool because the precious metal was disappointed.
During the California Gold Rush in the 1840s this term was often used because inexperienced prospectors claimed to be discovering gold but it was pyrite, consisting of worthless iron disulfide (FeS2).
Ironically speaking, pyrite crystals may contain little real gold, although it is notoriously difficult to extract.
Gold in the pyrite is sometimes referred to as “invisible gold,” because standard microscopes are not observable.
Gold is sometimes called “invisible gold” within the pyrite, as it is not observable by standard microscopes, but requires advanced scientific tools.
It wasn’t until the 1980s that scientists found that gold in pyrite could occur in various shapes, either as gold particles or as an alloy in which pyrite or gold are thoroughly blended.
In our new geology research, my friends and I discovered a third way that gold can lurk inside pyrite, that is previously unknown.
When the pyrite crystal forms at extreme temperature or pressure, its crystal structure may become “decorated” with gold atoms. it can produce tiny imperfections.
Scientists found out that gold can gather within the pyrite in the third previously unknown manner.
What are the ‘crystal faults’?
The atoms within a crystal are arranged in an atomic lattice pattern.
But when a pyrite-like mineral crystal grows in a rock, this pattern of grating may develop imperfections.
Pyritis, like many minerals, is hard on the earth’s surface, but when formed depths deeper into the Earth, where gold deposits also form, it may become more strained and twisted.
The bonds between surrounding atoms, when the crystals stretch or tweak, break away and recast form billions of small imperfections known as “dislocations” which are approximately 100,000 times smaller than human hair widths, or 100 times smaller than viral particles.
In Burkina Faso, Gold processing at the Poura gold mine.
A nuclear test can analyse materials at a very high resolution, but its main advantage over other methods is that we can create a 3D map that shows the exact locations of impurities within a crystal — a feature never seen before.
Our research shows that pyrite crystal dislocations can “decorate” with gold atoms.
This is particularly common when, in the course of their history, crystals have been twisted; gold can be present several times more than in the rest of the crystal.
Panning for gold, Senior Man.
A possible gold mine
Why should anyone care for such a small thing?
It provides interesting insights into the form of mineral deposits and is also a prospect for gold mining.
Earlier, gold was suspected of having been made from gold particles in anomally rich pyrital crystals that formed during a multi-step process, suggesting that it crystallised pyrite and gold at different times and then clumped.
However, our discovery that gold can decorate these crystal imperfections indicates that pyrite crystals with relatively high contents of gold can even form in one process.
Our findings can also help gold miners to extract gold from pyrite more effectively and potentially reduce greenhouse emissions.
The mineral, which consumes considerable energy for the extraction of gold, is often oxidated in large reactors.
In Queensland there is a new rush of gold with fossil fossiling people.
Dislocation sites within crystals can potentially offer an increase in partial or bacterial leaching to attack and break the crystal, release the “bio-leaching” process of the gold and thus reduce the energy consumption required for mining.
This idea is still untested, but it definitely deserves research.
If it helps pave the way for a more sustainable way of gold mining, the gold of fool may not be so stupid, after all.
Perhaps, until better and environmentally sustainable processing techniques are developed, pyrite still lives on its historic repute as “fool gold.”