Biggest Diamond in the World: Size, History, Value & Facts

Diamonds have fascinated people for centuries. From royal crowns to luxury jewelry, these sparkling stones symbolize power, beauty, and rarity. But among all diamonds ever discovered, one question continues to amaze gem lovers and historians alike: what is the biggest diamond in the world?

The biggest diamond in the world is not just impressive because of its size. It carries a remarkable story of discovery, expert craftsmanship, and royal history. Over time, several large diamonds have been discovered, but only a few truly qualify as the world’s biggest diamond or the largest diamond ever found.

In this guide, we’ll explore the history of the largest diamond in the world, how it was discovered, how it was cut, and how it compares to other famous stones. You’ll also learn about the largest cut diamond in the world, the difference between the most expensive diamond and the biggest one, and fascinating facts about the world’s greatest diamond treasures.

What Is the Biggest Diamond in the World?

The biggest diamond in the world refers to the largest rough diamond ever discovered in terms of weight (carats). In diamond terminology, “biggest” usually means the raw, uncut stone before it is shaped into gems.

The record holder is the Cullinan Diamond, a massive rough stone weighing 3,106 carats (about 621 grams).

To put that into perspective:

• It weighed more than half a kilogram

• It was about the size of a small fist

• It is considered the largest diamond ever discovered in recorded history

This extraordinary stone changed the history of diamonds forever. Even today, no other world big diamond has surpassed it in size.

However, when we talk about diamonds used in jewelry, we often refer to the largest cut diamond in the world, which is different from the original rough stone.

The Cullinan Diamond – The Largest Diamond Ever Found

Discovery Story

The legendary Cullinan Diamond was discovered in 1905 at the Premier Mine in South Africa.

A mine superintendent named Frederick Wells noticed something unusual shining in the mine wall about 18 feet underground. When he dug it out, he found an enormous crystal that looked almost unreal.

At first, people believed it was just a piece of glass because of its size. But after examination, it turned out to be the largest diamond ever found.

Important discovery facts:

• Year discovered: 1905

• Location: Premier Mine, South Africa

• Weight: 3,106 carats

• Named after: Thomas Cullinan, the mine owner

The stone was later presented to King Edward VII of the United Kingdom, marking the beginning of its royal journey.

Size, Weight & Features

The Cullinan Diamond is still considered the world’s biggest diamond in its rough form.

Key characteristics include:

• Weight: 3,106 carats

• Length: 10.1 cm

• Width: 6.35 cm

• Height: 5.9 cm

• Color: Exceptional white

• Clarity: Extremely high purity

Gem experts believe the original crystal might have been part of an even larger diamond world formation, suggesting the discovered piece was only a fragment.

Its incredible quality also placed it among the highest quality diamonds ever mined.

How It Was Cut

Because of its enormous size and value, cutting the Cullinan Diamond required extreme precision.

The task was given to the famous diamond company Asscher Brothers in Amsterdam.

In 1908, master cutter Joseph Asscher studied the stone for months before attempting the first cut.

Legend says:

• The first blade broke during the attempt.

• The second strike successfully split the diamond.

• Asscher reportedly fainted from relief after the cut.

The rough stone was eventually cut into 9 major diamonds and about 96 smaller gems.

The most famous pieces include:

• Cullinan I (Great Star of Africa) – 530.2 carats

• Cullinan II (Second Star of Africa) – 317.4 carats

These stones remain part of the British Crown Jewels.

Largest Cut Diamond in the World Today

While the Cullinan was the biggest diamond ever, the largest cut diamond in the world is determined by the size of a finished gemstone.

For many years, Cullinan I held the record.

Cullinan I – The Great Star of Africa

• Weight: 530.2 carats

• Cut: Pear-shaped brilliant

• Location: British Sovereign’s Sceptre

It remains one of the world’s greatest diamond treasures.

However, in 2019 another giant diamond entered the spotlight.

The Sewelo Diamond

Discovered in Botswana, the Sewelo Diamond weighed 1,758 carats in rough form. Though extremely large, it has not been fully cut into a finished gem like Cullinan I.

Because of this, Cullinan I is still widely considered the largest cut diamond world record holder used in royal regalia.

Top 7 Largest Diamonds in the World

Below is a table of the largest diamond world discoveries in history.

These stones represent some of the largest diamonds in the world, and many were later transformed into stunning jewels.

Most Expensive Diamond vs Biggest Diamond

Many people assume the most expensive diamond must also be the biggest diamond in the world, but that isn’t true.

Diamond value depends on multiple factors, not just size.

Why Bigger Doesn’t Always Mean More Valuable

A large diamond can still be less valuable if it has:

• Poor color

• Visible inclusions

• Weak cut quality

Meanwhile, a smaller diamond with perfect characteristics may be worth far more.

Examples of the Most Costly Diamonds

Some of the most costly diamonds ever sold include:

• Pink Star Diamond – sold for $71 million

• Oppenheimer Blue – sold for $57 million

• Wittelsbach-Graff Diamond – valued at over $80 million

These stones are extremely rare because of their color and clarity, even though they are much smaller than the largest diamond ever found.

What Determines Diamond Size and Quality?

Not every big diamond in the world becomes valuable. The quality of a diamond is judged using the 4Cs.

Cut

The cut determines how well a diamond reflects light.

A well-cut diamond will:

• Sparkle intensely

• Appear brighter

• Look more symmetrical

Even a large diamond can look dull if the cut is poor.

Clarity

Clarity refers to internal imperfections called inclusions.

Higher clarity diamonds:

• Have fewer visible flaws

• Are more transparent

• Command higher prices

Many highest quality diamonds are nearly flawless.

Color

Diamonds range from colorless to yellow or brown.

The most valuable diamonds are:

• Colorless (D-grade)

• Rare colored diamonds like blue, pink, and red

Some of the most expensive diamonds are colored diamonds rather than clear ones.

Carat

Carat measures weight.

Important facts:

• 1 carat = 0.2 grams

• Larger diamonds become exponentially rarer

This is why the largest diamond world discoveries attract so much attention.

Interesting Facts About Large Diamonds

Here are some fascinating facts about the world’s biggest diamond discoveries:

• The Cullinan Diamond was over 10 times larger than the Koh-i-Noor.

• Experts believe the Cullinan stone was only part of a much larger crystal.

• Some large diamonds are discovered by accident during routine mining.

• The largest diamond ever found required months of planning before cutting.

• The Cullinan gems are still part of the British Crown Jewels today.

• Many large diamonds are cut into multiple smaller stones to maximize value.

These discoveries continue to shape the history of gemstones and luxury jewelry.

Conclusion

The story of the biggest diamond in the world is one of discovery, craftsmanship, and royal history. From its dramatic discovery in South Africa to its transformation into some of the most famous gems ever created, the Cullinan Diamond remains unmatched.

Even today, it holds the title of the largest diamond ever found, while Cullinan I continues to be celebrated as one of the largest cut diamonds in the world.

Although newer discoveries like the Sewelo and Lesedi La Rona have stunned the diamond industry, none have yet surpassed the legacy of the Cullinan.

Understanding these historic stones also helps us appreciate how rare large diamonds truly are. Their beauty, size, and rarity make them some of the world’s greatest diamond treasures — admired by collectors, historians, and jewelry lovers alike.

Whether you’re fascinated by the world big diamond discoveries, searching for the largest diamond ring, or curious about the most costly diamond ever sold, one thing is clear: diamonds continue to capture human imagination like no other gemstone.