Gemfields Just Unearthed a Record-Breaking Emerald: Meet ‘Imboo’

Mining company Gemfields has just announced the discovery of a massive 11,685-carat exceptional-quality rough emerald from its Kagem mine in Zambia, naming the colossal gem “Imboo,” which means “buffalo” in the local Bemba language.

You’ve likely just seen a headline about a gigantic green gemstone flash across your news feed. You see an incredible number—over 11,000 carats—and you’re probably wondering: What does that even mean? Is this a priceless treasure? What happens to a stone this massive? And does a find like this affect the emeralds I might want to buy?

As your friend in the business, I’m here to go beyond the press release. We are going to dive into the real story of this incredible discovery. I’ll explain exactly why this ‘Imboo’ emerald is so significant, what will likely happen to it next, and what it tells us about the world of fine emeralds. Let’s get into the insider details.

Unearthing a Masterpiece From Nature’s Hand

Every so often, the earth gives up a secret so spectacular that it sends a ripple of excitement through the entire gemological world. The discovery of the “Imboo” emerald is one of those moments.

But to truly appreciate its significance, you have to understand the incredible confluence of factors—the sheer size, the perfect location, and the right people—that came together to make it possible.

The “What”: A True Behemoth

Let’s start with the headline number, because it’s genuinely staggering. The “Imboo” is an 11,685-carat rough emerald. To put that in perspective, that’s roughly 5.15 pounds (or 2.34 kg). Imagine a gem-quality crystal the size of a small melon.

This isn’t just another big stone; it’s a behemoth, a true monster of nature that instantly enters the history books as the largest exceptional-quality emerald ever discovered at the Kagem mine.

But in the world of gemstones, size is only part of the story; quality is everything. And this is where Imboo truly shines. According to Gemfields’ own experts, the stone reveals an “intense, verdant green touched with golden warmth.” 

This is key. “Verdant green” tells us it has that rich, pure color that is the hallmark of the finest emeralds, while the “golden warmth” is a signature of high-quality Zambian stones. This isn’t just a giant crystal; it’s a giant crystal of exceptional color and clarity.

The Name: A Tribute to a Zambian Giant

In a beautiful tradition, Gemfields often names its most significant discoveries after Zambian wildlife, turning these gems into legendary figures. This stone has been christened “Imboo” (pronounced im-bow), which is the word for “buffalo” in the local Bemba language.

The name was chosen to honor the buffalo’s own legendary status in the African bush—an animal known for its sheer size, its strength, and its deep sense of community. As the Kagem mine’s grading manager, Jackson Mtonga, said, “The immense size and nature of the crystal formation makes it fitting that this unique piece is given the name ‘buffalo’.”

The “Where”: A Legendary Treasure Chest

A stone this significant couldn’t have come from just anywhere. It was discovered deep within the Chama pit of the Kagem mine in Zambia.

For those of us in the industry, the Chama pit is legendary. It’s the specific part of the mine that has become world-famous for producing these colossal, world-class emeralds.

The reason for this is a geological “perfect storm.” Here’s the simple, non-geologist’s explanation: The Chama pit is what’s known as a “triple junction,” a rare spot where three completely different types of rock and geological structures smash together.

This violent intersection creates an incredibly unique, high-pressure, and mineral-rich environment—the perfect pressure-cooker for growing emerald crystals.

The space and the availability of the key ingredients (beryllium, chromium, and vanadium) in this specific zone are what allow crystals to form not just with great color, but also with this kind of enormous size. It’s a freak of nature, and it’s the secret sauce behind Kagem’s giants.

The “Who”: The Right People at the Right Time

Finally, a discovery like this is never an accident. On August 3, 2025, it was veteran geologist Dharanidhar Seth and a highly experienced miner named Justin Banda who unearthed Imboo.

Mr. Banda has reportedly been instrumental in the discovery of many of Kagem’s most important stones. It’s a powerful reminder that even with all of today’s technology, the discovery of a true masterpiece from nature’s hand often comes down to the experience, knowledge, and sheer determination of the people on the ground.

What Happens to a Giant Emerald Like Imboo?

So, the biggest and most obvious question when you see an 11,685-carat gemstone is: what on earth do they do with it? Do they just polish the outside and put it in a museum? The answer is much more complex and, frankly, far more interesting.

A discovery like this isn’t the end of a journey; it’s the beginning of a long and painstaking process that will transform this single rough crystal into potentially dozens of flawless, priceless gems.

The Journey from Rough to Royal

Let’s be very clear: a stone of this immense size will never be kept as one single piece. Its ultimate destiny is to be carefully studied and then strategically cut and polished into many smaller, but still very significant, top-quality emeralds.

The process is a masterclass in patience and precision:

1. Months of Study: First, the new owner of Imboo will likely spend months, if not a year or more, just looking at it.
   Gemological experts will use advanced scanning technology to map the stone’s interior, identifying its natural crystal structure, its fissures, and its inclusions. They are creating a 3D blueprint of the entire stone.
   
2. The Master Plan: Based on this blueprint, a team of master cutters will plot the optimal way to cut the stone. Their goal is to maximize the yield of high-quality, gem-grade emeralds while cutting away all the imperfections.
   They might plan to get three or four massive, flawless gems of over 100 carats each, dozens of 10-to-50-carat stones, and perhaps hundreds of smaller accent stones.
   
3. The First Cut: The single most nerve-wracking moment in this process is the first time the rough stone is sawn or cleaved. This first cut, which determines the fate of the entire treasure, is planned with meticulous care.

As Gemfields’ own Managing Director of Product and Sales, Adrian Banks, explained, “It is easy to imagine Imboo giving rise to several fine-quality cut emeralds of significant size. Such a rare collection could form an entire high-jewelry suite from this single gemstone.” And that is the true destiny of a stone like this.

A Case Study: The “Insofu” Emerald’s Glorious Fate

To understand what will likely happen to Imboo, we have a perfect real-world example: the 6,225-carat “Insofu” (Elephant) emerald, discovered in this very same Chama pit back in 2010.

After its discovery, the Insofu was purchased by the world-famous luxury jewelry house, Chopard. They didn’t just buy a stone; they bought a story. Chopard’s master artisans then embarked on the long journey of transforming that single rough crystal into the “Insofu” high-jewelry collection.

The final result was a complete suite of breathtaking jewelry—necklaces, earrings, rings, and even a watch—all featuring perfectly cut and flawlessly matched emeralds.

This is the ultimate prize for a high-jewelry brand. Normally, finding even five large emeralds with the exact same color, hue, and saturation is an almost impossible task. But because all the gems in the Insofu collection were born from the same mother stone, they share the exact same DNA.

They are a perfect, harmonious family. This is the likely, and most glorious, future for Imboo: it will one day re-emerge on the world stage as a spectacular, one-of-a-kind collection from a legendary jewelry house.

Will This Discovery Make Emeralds Cheaper?

This is the question every savvy buyer asks. When a massive gem is found, does that new supply cause the price of all emeralds to drop?

The short and definitive answer is no. Absolutely not.

A discovery like this has the opposite effect. A single, headline-grabbing stone doesn’t flood the market with inventory; it floods the market with excitement.

• It Reinforces Rarity: A find of this magnitude is a once-in-a-decade event. It serves as a powerful global reminder of just how special and rare a truly fine Zambian emerald is.
  
• It Boosts Prestige: The news of the Imboo puts the Kagem mine and Zambian emeralds in the headlines, increasing their name recognition and prestige among collectors and jewelry lovers.
  
• It Doesn’t Change Market Supply: The dozens of polished gems that will eventually come from Imboo will be absorbed into the very highest end of the exclusive luxury market, not the commercial market where most of us shop.

A discovery this rare doesn’t decrease the value of emeralds; it burnishes the legend and reinforces the desirability of all high-quality Zambian gems.

Imboo is the Largest, but It’s Not the First

While the sheer size of the Imboo emerald is a record-breaker, its discovery is not an isolated event. In fact, Imboo is just the latest, and most spectacular, addition to a legendary family of giant emeralds that have been unearthed from this very same part of the Kagem mine. This specific area, the Chama pit, has a proven history of producing colossal treasures.

Recognizing the significance of these finds, Gemfields has established a beautiful tradition of naming its most important discoveries after Zambia’s majestic wildlife.

This practice doesn’t just give the stones an identity; it creates a lasting legacy, transforming each gem from a simple mineral into a named, legendary figure in the world of gemology.

Imboo the “Buffalo” now joins an exclusive “Hall of Fame”—a pride of lions, a herd of elephants, a crash of rhinos, and now, a journey of buffalo, all born from the same miraculous corner of the earth. Here is the official roll call of the “Giants of the Chama Pit.”

The Gem	Name Meaning	Year Found	Carat Weight
Imboo	The Buffalo	2025	11,685 ct.
Chipembele	The Rhino	2021	7,525 ct.
Inkalamu	The Lion	2018	5,655 ct.
Insofu	The Elephant	2010	6,225 ct.

As you can see, the discovery of a world-class, named emerald has become a defining characteristic of the Kagem mine over the last 15 years. This isn’t just a list of big stones; it’s a proven track record.

This “Hall of Fame” is what gives collectors and connoisseurs such immense confidence in the source. The Chama pit is not just a fluke; it is a reliable, scientifically understood phenomenon that consistently produces emeralds of a size and quality found almost nowhere else on Earth.

The addition of Imboo as the new king of this list only further solidifies the Kagem mine’s legendary status.

What is “Provenance Proof Nanoparticle-Tagging”?

When Gemfields announced the discovery of Imboo, they included a fascinating piece of information that most reports just glossed over: the new owner will be offered the chance to use a technology called Provenance Proof nanoparticle-tagging.

Now, that sounds like something out of a science fiction movie, but it’s actually a groundbreaking piece of technology that solves one of the oldest problems in the gem trade.

As your friend in the business, I want to pull back the curtain and explain what it is and why it’s so important.

The Old Problem: A Broken Chain of Custody

Let’s go back to our case study of the “Insofu” emerald that was cut up to create a magnificent jewelry collection. Once that 6,225-carat rough crystal is transformed into 50 or 100 smaller, polished emeralds, a major problem arises: how can you prove that a specific 5-carat emerald in an earring came from that original, legendary mother stone?

For centuries, the answer has been a paper trail—a series of documents, certificates, and the word of a trusted jewelry house. But paper can be lost, and stories can be embellished. There was no way to scientifically link a polished gem back to its original rough crystal.

The Modern Solution: A “Digital DNA” for Gemstones

This is where the new technology comes in. The company Provenance Proof, a Swiss gemological lab, has developed a way to create a permanent, unbreakable link between a gemstone and its source.

Here’s the simple version of how it works:

1. Infusion: Before the Imboo is cut, a solution containing infinitesimally small nanoparticles is gently infused into the natural fissures of the rough crystal. These nanoparticles are completely invisible to the naked eye and have zero effect on the emerald’s appearance or quality.
   
2. Unique Signature: These nanoparticles are essentially a high-tech “digital DNA.” Each one contains a unique, encrypted code that is recorded on a secure, blockchain-based digital ledger. This code is now forever tied to the Imboo.
   
3. Verification: Even after the Imboo is cut into dozens of smaller gems, those invisible nanoparticles will still be present inside each and every stone.
   At any point in the future, a gemologist with a special scanner can detect these particles, read their unique code, and instantly verify with 100% certainty that this specific gem was once part of that historic 11,685-carat rough crystal.

Why It Matters to a Collector

This technology provides the ultimate guarantee of provenance.

It’s the difference between hearing a good story and holding a signed first-edition copy of a classic book. It is irrefutable, scientific proof of a gemstone’s origin. For the final collector, this is a massive deal.

It adds an incredible layer of security, romance, and, ultimately, value to their purchase. They are not just buying a beautiful emerald; they are buying a verifiable piece of history, a authenticated sliver of the legendary “Imboo” buffalo.

Your Top Questions About This Discovery

A find like the Imboo emerald is exciting, but it also brings up a lot of questions. Let’s tackle the most common ones with some clear, direct answers so you can understand the full context of this historic discovery.

The Verdict: A Masterpiece of Nature Enters the History Books

The discovery of the Imboo emerald is more than just a mining update; it’s a major event in the gemological world. It reinforces the Kagem mine’s status as a source of legendary stones and provides a fascinating look into the journey from deep within the earth to the world’s most exclusive jewelry collections.

While you may never own a piece of the Imboo itself, understanding its story gives you a deeper appreciation for the beauty, rarity, and the incredible journey of every fine emerald. This is the kind of provenance and wonder that makes the world of gemstones so captivating.