The Times Australia
The Times World News

.
The Times Real Estate

.

'fool's gold' contains a newly discovered type of real gold

  • Written by Denis Fougerouse, Research Fellow, School of Earth and Planetary Sciences, Curtin University

The mineral pyrite was historically nicknamed fool’s gold[1] because of its deceptive resemblance to the precious metal. The term was often used during the California gold rush in the 1840s because inexperienced prospectors would claim discoveries of gold, but in reality it would be pyrite, composed of worthless iron disulfide (FeS₂).

Ironically, pyrite crystals can contain small amounts of real gold, although it is notoriously hard to extract. Gold hiding within pyrite is sometimes referred to as “invisible gold”, because it is not observable with standard microscopes, but instead requires sophisticated scientific instruments.

It wasn’t until the 1980s when researchers discovered[2] that gold in pyrite can come in different forms – either as particles of gold, or as an alloy, in which the pyrite and gold are finely mixed.

In our new research, published in Geology[3], my colleagues and I discovered a third, previously unrecognised way that gold can lurk inside pyrite. When the pyrite crystal is forming under extreme temperature or pressure, it can develop tiny imperfections in its crystal structure that can be “decorated” with gold atoms.

What are these ‘crystal defects’?

The atoms within a crystal are arranged in a characteristic pattern called an atomic lattice. But when a mineral crystal such as pyrite is growing inside a rock, this lattice pattern can develop imperfections. Like many minerals, pyrite is tough and hard at Earth’s surface, but can become more twisty and stretchy when forming deep in the Earth, which is also where gold deposits form.

When crystals stretch or twist, the bonds between neighbouring atoms are broken and remade, forming billions of tiny imperfections called “dislocations”, each roughly 100,000 times smaller than the width of a human hair, or 100 times smaller than a virus particle.

The chemistry of these atomic-scale imperfections is notoriously difficult to study because they are so small, so any impurities are present in absolutely minuscule quantities. Detecting them requires a specialised instrument called an atom probe[4].

An atom probe can analyse materials at extremely high resolution, but its main advantage over other methods is that it allows us to build a 3D map showing the precise locations of impurities within a crystal — something that was never possible before.

Our research reveals that dislocations within pyrite crystals can be “decorated” with gold atoms. This is particularly common where the crystals have been twisted during their history; here, gold can be present at concentrations several times higher than in the rest of the crystal.

Impurities in pyrite crystal Gold (Au) atoms hiding within a pyrite crystal, alongside other imperfections including nickel, copper and bismuth. Scale bar indicates 20 nanometres. Author provided

A potential goldmine

Why should anyone care about something so tiny? Well, it gives interesting insights into how mineral deposits form, and is also a potential boon for the gold mining industry.

Previously, it was suspected that gold in anomalously rich pyrite crystals was in fact made of gold particles formed during a multi-step process, suggesting the pyrite and gold crystallised at different times and then became clumped together. But our discovery that gold can decorate these crystal imperfections suggests that even pyrite crystals with relatively high gold content can form in a single process.

Read more: Eureka! X-ray vision can find hidden gold[5]

Our discovery may also help gold miners more efficiently extract gold from pyrite, potentially reducing greenhouse emissions. To extract the gold, the mineral is usually oxidised in large reactors, which uses considerable amounts of energy.

Dislocation sites within crystals could potentially offer an enhanced partial leaching or a target for bacteria to attack and break down the crystal, releasing the gold in a process known as “bio-leaching”, thus potentially reducing energy consumption necessary for extraction. This idea is still untested, but definitely merits investigation.

If it helps pave the way for more sustainable gold-mining methods, then perhaps fool’s gold isn’t so foolish after all.

Perhaps pyrite still lives up to its historic reputation of “fool’s gold” until better, more environmentally sustainable ore processing techniques are developed.

Read more: How gold rushes helped make the modern world[6]

References

  1. ^ fool’s gold (www.britannica.com)
  2. ^ researchers discovered (www.researchgate.net)
  3. ^ published in Geology (pubs.geoscienceworld.org)
  4. ^ atom probe (youtube.com)
  5. ^ Eureka! X-ray vision can find hidden gold (theconversation.com)
  6. ^ How gold rushes helped make the modern world (theconversation.com)

Read more https://theconversation.com/not-so-foolish-after-all-fools-gold-contains-a-newly-discovered-type-of-real-gold-161819

The Times Features

Best Deals on Home Furniture Online

Key Highlights Discover the best deals on high-quality outdoor furniture online. Transform your outdoor space into a stylish and comfortable oasis. Explore a wide range of d...

Discover the Best Women's Jumpers for Every Season

Key Highlights Explore lightweight jumpers for spring and summer, ensuring breathability and ease. Wrap up warm with cozy wool jumpers for the chilly autumn and winter season...

Uncover the Elegance of Gorgeous Diamond Tennis Necklaces

Key Highlights Diamond tennis necklaces are a timeless piece of jewelry that exudes elegance and sophistication. They feature a continuous line of brilliant-cut diamonds, cre...

Dental Implants vs. Dentures: Which Is Better for You?

When it comes to replacing missing teeth, two of the most common options are dental implants and dentures. Both have their advantages and disadvantages, so choosing between them ...

What Neck Pain Really Means (And Why It’s More Than Just Poor Posture)

Neck pain is often brushed off as something temporary — a tight spot after a long day at the desk or a poor night’s sleep. But when the discomfort keeps returning, it could be a ...

The Work of Gosha Rubchinskiy: Fashion, Culture, and Youth

From Designer to Cultural Architect Gosha Rubchinskiy is not just a fashion designer—he's a cultural force. Born in Moscow in 1984, Rubchinskiy began his career in fashion in t...

Times Magazine

The Essential Guide to Transforming Office Spaces for Maximum Efficiency

Why Office Fitouts MatterA well-designed office can make all the difference in productivity, employee satisfaction, and client impressions. Businesses of all sizes are investing in updated office spaces to create environments that foster collaborat...

The A/B Testing Revolution: How AI Optimized Landing Pages Without Human Input

A/B testing was always integral to the web-based marketing world. Was there a button that converted better? Marketing could pit one against the other and see which option worked better. This was always through human observation, and over time, as d...

Using Countdown Timers in Email: Do They Really Increase Conversions?

In a world that's always on, where marketers are attempting to entice a subscriber and get them to convert on the same screen with one email, the power of urgency is sometimes the essential element needed. One of the most popular ways to create urg...

Types of Software Consultants

In today's technology-driven world, businesses often seek the expertise of software consultants to navigate complex software needs. There are several types of software consultants, including solution architects, project managers, and user experienc...

CWU Assistive Tech Hub is Changing Lives: Win a Free Rollator Walker This Easter!

🌟 Mobility. Independence. Community. All in One. This Easter, the CWU Assistive Tech Hub is pleased to support the Banyule community by giving away a rollator walker. The giveaway will take place during the Macleod Village Easter Egg Hunt & Ma...

"Eternal Nurture" by Cara Barilla: A Timeless Collection of Wisdom and Healing

Renowned Sydney-born author and educator Cara Barilla has released her latest book, Eternal Nurture, a profound collection of inspirational quotes designed to support mindfulness, emotional healing, and personal growth. With a deep commitment to ...

LayBy Shopping