Best Diamonds in the World: Biggest, Largest, Smallest, Most Expensive, Cheapest and Types of Diamonds

Diamonds have fascinated people for centuries. They are symbols of love, wealth, power, beauty and rarity, but not every diamond is the same. Some are famous because they are incredibly large, others because of their extraordinary color, history, rarity or record-breaking price.

If you are searching for the best diamonds in the world, you will quickly discover that “best” does not have one single definition. The best diamond for a collector may be a historically important gemstone such as the Hope Diamond. For an investor or luxury buyer, a rare vivid pink or blue diamond may be more desirable. For someone buying an engagement ring, the best diamond may simply be one that offers excellent beauty and value within their budget.

This complete guide explores the world of exceptional diamonds, including the biggest diamonds, largest diamonds, smallest diamonds, most expensive diamonds, cheaper diamonds and different types of diamonds. It also explains what makes a diamond valuable and how to choose the right diamond.

What Are the Best Diamonds in the World?

The phrase “best diamonds in the world” can refer to diamonds that stand out because of their size, color, clarity, cut, history, rarity or auction price.

There is no universal ranking that determines which diamond is absolutely the best. Diamonds are evaluated according to different characteristics, and a diamond that is considered extraordinary in one category may not be the best in another.

For example:

The Cullinan is famous for its extraordinary rough size.
The CTF Pink Star is famous for its record auction price and exceptional pink color.
The Hope Diamond is famous for its blue color, history and cultural significance.
The Koh-i-Noor is famous for its historical importance.
Red diamonds are famous for extreme rarity.
High-quality colorless diamonds are prized for their brilliance and purity.

The Gemological Institute of America (GIA) notes that fancy-color diamonds are among the rarest and most valuable gemstones, with saturated pink, blue and green diamonds particularly prized.

So, when discussing the best diamonds in the world, it is more useful to look at diamonds by category rather than simply creating one ranking.

The 10 Most Famous Diamonds in the World

Several diamonds have become famous far beyond the jewelry industry. Their stories involve royalty, explorers, wealthy collectors, historic mines and international auctions.

Here are some of the world’s most famous diamonds.

1. Cullinan Diamond

The Cullinan Diamond is one of the most important diamonds ever discovered.

Found in South Africa in 1905, the original rough diamond weighed approximately 3,106 carats. Guinness World Records recognizes the Cullinan as the largest gem-quality rough diamond discovered. It was eventually cut into numerous polished diamonds.

Among the most famous stones produced from it are:

Cullinan I
Cullinan II
Cullinan III
Cullinan IV
Cullinan V
Cullinan VI
Cullinan VII
Cullinan VIII
Cullinan IX

Cullinan I, also called the Great Star of Africa, weighs 530.2 carats and became one of the world’s most famous cut diamonds.

Why is the Cullinan so famous?

Its importance comes primarily from its enormous original size and the extraordinary collection of high-quality diamonds produced from the rough.

It is therefore one of the strongest candidates for the title of biggest diamond in the world, when discussing rough gem-quality diamonds.

2. Hope Diamond

The Hope Diamond is perhaps the most famous blue diamond in the world.

It weighs 45.52 carats and is classified by GIA as a Fancy Deep grayish-blue diamond. GIA describes it as the world’s most famous gem.

Its distinctive blue color is connected to trace amounts of boron. Blue diamonds are exceptionally rare, and their color can make them extremely valuable.

The Hope Diamond is also famous for its long and fascinating history, including stories of royalty, wealthy owners and the legendary “curse” associated with the stone.

Whether the curse is fact or folklore, the diamond’s combination of size, color, history and fame makes it one of the world’s most recognizable gemstones.

3. CTF Pink Star

The CTF Pink Star is one of the greatest examples of a rare fancy-color diamond.

It weighs 59.60 carats and is graded Fancy Vivid Pink and Internally Flawless.

In 2017, it sold at Sotheby’s Hong Kong for approximately $71.2 million, making it the most expensive diamond ever sold at auction. Sotheby’s continues to identify it as the auction record holder for a gemstone or jewel.

The original rough diamond reportedly weighed 132.5 carats before being cut and polished.

Why is the Pink Star so valuable?

Its value comes from a combination of:

Exceptional pink color
Fancy Vivid color grade
Large carat weight
Internally Flawless clarity
Rarity
International auction demand

The CTF Pink Star demonstrates why a smaller colored diamond can sometimes be worth much more than a much larger colorless diamond.

4. Koh-i-Noor

The Koh-i-Noor is one of the most historically famous diamonds in existence.

Its name means “Mountain of Light.”

The diamond has a long history associated with rulers and empires in South Asia before eventually becoming part of the British Crown Jewels.

Unlike a modern auction diamond, its importance cannot be measured simply by a market price. Its historical and political significance is a major part of its identity.

The Koh-i-Noor illustrates an important point: the value of a famous diamond is not always determined by carat weight or auction price.

5. Regent Diamond

The Regent Diamond is another legendary diamond associated with European royalty.

It is famous for its exceptional quality, historical importance and association with French royal jewelry.

The diamond is a classic example of how provenance can transform a gemstone from a beautiful object into a major historical artifact.

6. Orlov Diamond

The Orlov Diamond is a large historic diamond with a distinctive shape and fascinating history.

It is traditionally associated with India and later became part of the Russian imperial collection.

Its unusual appearance and historical journey make it one of the world’s famous diamonds.

7. Dresden Green Diamond

The Dresden Green is one of the most famous natural green diamonds.

Green diamonds are unusual because their color is generally associated with natural radiation exposure during the diamond’s geological history.

Natural green diamonds are rare, and the Dresden Green is particularly famous for its strong green color and historical significance.

GIA notes that natural fancy green diamonds are generally unusual and that their color often has characteristics that distinguish them from other fancy colors.

8. Blue Moon of Josephine

The Blue Moon of Josephine is an extraordinary blue diamond.

Its vivid blue color and high clarity helped make it one of the most valuable colored diamonds ever sold.

The diamond demonstrates how dramatically rarity can influence price. A blue diamond of exceptional color can command a premium far beyond a conventional colorless diamond of similar size.

9. The Graff Pink

The Graff Pink is another legendary pink diamond.

Originally weighing approximately 24.78 carats, it was later recut to about 23.88 carats.

Its vivid pink color and exceptional clarity contributed to its enormous auction value.

Sotheby’s lists the Graff Pink among the most expensive pink diamonds ever sold, with a reported auction price of approximately $46 million.

10. Williamson Pink Star

The Williamson Pink Star is another remarkable pink diamond.

Weighing 11.15 carats, it achieved approximately $57.5 million at Sotheby’s Hong Kong in 2022.

Its price demonstrates the extraordinary premium that collectors can place on rare, high-quality pink diamonds.

Biggest and Largest Diamonds in the World

When people search for the biggest diamond in the world, there is an important distinction between a rough diamond and a polished diamond.

A rough diamond is the stone as it comes from the mine. A polished diamond has been cut and shaped for jewelry.

The largest rough diamond ever recognized in the gem-quality category is the Cullinan, at approximately 3,106 carats.

But cutting a diamond involves removing material. Therefore, the largest rough diamond does not necessarily become the largest polished diamond.

Why Aren’t All Big Diamonds Extremely Valuable?

Size is only one factor.

Imagine two diamonds:

Diamond A

10 carats
Poor color
Low clarity
Weak cut

Diamond B

5 carats
Exceptional color
Excellent clarity
Excellent cut

Diamond B could potentially be more valuable than Diamond A.

This is because diamond pricing depends on multiple characteristics rather than weight alone.

What Is the Smallest Diamond?

The term “smallest diamond” can be misleading.

Diamonds can be extremely tiny, including microscopic natural diamonds and tiny diamonds used in jewelry manufacturing.

There is no single universally accepted “smallest diamond in the world” in the same way that the Cullinan provides a famous benchmark for the largest gem-quality rough diamond.

Tiny diamonds are commonly known as:

Melee diamonds
Pave diamonds
Accent diamonds
Small brilliant diamonds
Diamond dust or industrial diamond particles

In jewelry, small diamonds are often used to surround a larger center stone or create continuous sparkle across a ring or bracelet.

The fact that a diamond is tiny does not mean it is worthless. Its value depends on quality, rarity, quantity and intended use.

Types of Diamonds

One of the most important parts of understanding the diamond market is knowing that “types of diamonds” can mean several different things.

Diamonds can be classified according to:

Origin
Color
Crystal characteristics
Cut
Shape
Treatment

Let’s examine the major categories.

1. Natural Diamonds

Natural diamonds are formed naturally inside the Earth over geological timescales.

They consist essentially of crystallized carbon arranged in a cubic crystal structure.

Natural diamonds can be colorless, near-colorless, yellow, brown, pink, blue, green, red and many other colors.

They can also contain different types of inclusions and impurities that help gemologists determine their characteristics and sometimes their origin.

Natural diamonds remain the traditional choice for many luxury jewelry buyers.

2. Laboratory-Grown Diamonds

Laboratory-grown diamonds are diamonds created using technological processes rather than geological formation.

The two major growth technologies are:

HPHT — High Pressure High Temperature
CVD — Chemical Vapor Deposition

GIA explains that laboratory-grown diamonds possess essentially the same chemical, physical and optical properties as natural diamonds, although their growth history is different.

Laboratory-grown diamonds have expanded consumer choice and are often available at lower prices than comparable natural diamonds.

However, buyers should understand that lab-grown does not mean fake.

A laboratory-grown diamond is a diamond; it is simply created through a different process.

3. Fancy-Color Diamonds

Fancy-color diamonds are diamonds whose color falls outside the normal D-to-Z color range.

They can occur in colors such as:

Pink
Blue
Green
Red
Orange
Yellow
Purple
Brown
Gray
Black

GIA states that red, green, purple and orange diamonds are among the rarest fancy colors, while pink and blue diamonds are also exceptionally valuable.

For fancy-color diamonds, stronger and purer color can dramatically increase value.

4. Colorless Diamonds

Colorless diamonds are graded using the D-to-Z color scale.

D represents the highest color grade, while lower grades show increasing traces of yellow or brown.

For traditional colorless diamonds, less visible body color is generally more desirable.

However, this does not mean every D-color diamond is automatically better than every lower-color diamond. Cut, clarity, carat weight and other factors still matter.

5. Yellow Diamonds

Yellow diamonds are among the more popular fancy-color diamonds.

They can range from light yellow to vivid yellow.

When a yellow diamond reaches the fancy-color range, its color becomes an important value factor.

A vivid yellow diamond can be highly desirable, especially when it has strong saturation and an attractive appearance.

6. Pink Diamonds

Pink diamonds are among the most desirable fancy-color diamonds.

The Argyle mine in Australia was historically a major source of pink diamonds, and its closure in 2020 significantly changed the supply landscape for these stones. Sotheby’s notes that around 80% of relatively recent pink-diamond production came from Argyle.

Pink diamonds can command extraordinary prices when they combine:

Strong color
Attractive hue
Large size
High clarity
Good cut
Desirable provenance

7. Blue Diamonds

Blue diamonds are among the rarest diamonds.

Their blue color is generally associated with boron impurities within the diamond’s crystal structure.

According to GIA, the deeper the blue, the more boron may be present, although the relationship is not simply a matter of “more boron equals more value.”

Famous blue diamonds include:

Hope Diamond
Blue Moon of Josephine
Oppenheimer Blue

8. Red Diamonds

Red diamonds are among the rarest natural diamonds known.

Pure red diamonds are extraordinarily uncommon.

Unlike blue diamonds, where boron plays a major role in color, the origin of red coloration is associated with structural deformation within the diamond.

Because of their extreme rarity, even relatively small red diamonds can be highly valuable.

9. Green Diamonds

Natural green diamonds are unusual.

Their color is commonly related to natural radiation exposure during their geological history.

The Dresden Green is perhaps the most famous example.

Natural green diamonds must be distinguished from treated diamonds that have been artificially colored.

10. Black Diamonds

Black diamonds are another distinctive category.

They can owe their appearance to numerous inclusions, particularly graphite and other minerals.

Some black diamonds are natural, while others may be treated to produce or enhance their color.

Because treatment can affect value, buyers should check the laboratory report and disclosure information.

The 4Cs: How Diamond Quality Is Determined

If you want to identify the best diamond for your needs, learning the 4Cs is essential.

The 4Cs are:

Cut
Color
Clarity
Carat Weight

They were developed as a standardized way to describe diamond quality.

1. Cut

Cut is one of the most important factors influencing a diamond’s visual appearance.

A well-cut diamond can return light beautifully and appear bright and lively.

Cut should not be confused with shape.

For example:

Shape

Round
Oval
Princess
Cushion
Emerald
Pear
Marquise

Cut quality

Excellent
Very Good
Good
Fair
Poor

For many buyers, an excellent cut can be more visually important than simply choosing a larger carat weight.

2. Color

For traditional colorless diamonds, color is graded from D to Z.

The closer the diamond is to D, the less noticeable body color it has.

However, fancy-color diamonds work differently.

GIA explains that color is the dominant value factor for fancy-color diamonds, and strong, vivid pinks, blues and greens can be exceptionally valuable.

3. Clarity

Clarity describes internal and external characteristics called inclusions and blemishes.

Common clarity grades include:

FL — Flawless
IF — Internally Flawless
VVS1
VVS2
VS1
VS2
SI1
SI2
I1
I2
I3

A flawless diamond is extremely rare.

However, buying the highest possible clarity is not always necessary.

Many VS or SI diamonds can look completely clean to the naked eye while costing considerably less than flawless stones.

4. Carat Weight

Carat measures diamond weight.

One carat equals 200 milligrams.

Carat is not the same as physical size.

Two diamonds with the same carat weight can appear different in size because their proportions and cuts are different.

Large diamonds are generally rarer than small diamonds, which is why price per carat can increase significantly as size increases.

What Is the Most Expensive Diamond in the World?

If we are talking specifically about a public auction record, the CTF Pink Star holds the distinction of being the most expensive diamond sold at auction.

It sold for $71.2 million in Hong Kong in 2017.

However, the phrase “most expensive diamond in the world” needs a qualification.

Some historically important diamonds are not regularly traded, so there is no reliable current market price for them.

Therefore, it is better to say:

The CTF Pink Star holds the auction record for the most expensive diamond sold publicly.

Why Are Some Diamonds So Expensive?

A diamond’s price can be influenced by several factors.

Rarity

The rarer the combination of characteristics, the more valuable the diamond may become.

Color

Color is particularly important for fancy-color diamonds.

Size

Large diamonds are much rarer than small diamonds.

Clarity

Higher clarity can increase value, particularly when combined with large size and desirable color.

Cut

Excellent cutting can improve brilliance, fire and overall appearance.

Provenance

A diamond with an important historical connection can command a significant premium.

Auction Demand

High-profile collectors competing for an exceptional diamond can drive prices dramatically upward.

Certification

An independent laboratory report can provide important information about a diamond’s characteristics and identity.

What Are the Cheapest Diamonds?

The term “cheapest diamond” does not necessarily mean a bad diamond.

Affordable diamonds can be found by making sensible compromises.

For example, buyers can consider:

Smaller carat weights
Lower clarity grades that remain eye-clean
Lower color grades
Alternative shapes
Lab-grown diamonds
Commercial-quality melee diamonds

Laboratory-grown diamonds can often offer a lower purchase price than comparable natural diamonds because their supply is not constrained by natural geological formation.

However, buyers should compare actual specifications and certification rather than assuming every lab-grown diamond or every natural diamond is automatically a bargain.

How to Buy a Cheaper Diamond Without Sacrificing Beauty

You don’t always need to buy a D-color, Flawless, 2-carat diamond to get a beautiful ring.

Here are some practical strategies.

Choose Eye-Clean Clarity

Instead of paying a huge premium for flawless clarity, look for a diamond that appears clean to the naked eye.

VS and some SI diamonds can provide excellent visual value depending on the stone.

Consider G-H Color

For many jewelry designs, G or H color can appear very white while costing less than D or E.

Choose an Oval or Cushion

Fancy shapes can sometimes provide more apparent size per carat than a round diamond.

Consider Lab-Grown

Laboratory-grown diamonds can offer substantial savings compared with natural diamonds of similar specifications.

Prioritize Cut

A beautifully cut diamond can appear brighter and more impressive than a larger poorly cut diamond.

Natural Diamond vs Laboratory-Grown Diamond

One of the biggest questions modern diamond buyers face is whether to choose a natural or laboratory-grown diamond.

Feature	Natural Diamond	Laboratory-Grown Diamond
Origin	Formed naturally in Earth	Created in a laboratory
Composition	Diamond	Diamond
Physical properties	Diamond	Essentially the same
Typical price	Higher	Often lower
Rarity	Natural geological rarity	Manufactured supply
History	Geological	Modern technological
Investment perception	Traditionally stronger	Different resale dynamics
Certification	Available	Available

GIA explains that laboratory-grown diamonds have essentially the same chemical, physical and optical properties as natural diamonds, while their growth processes are different.

The right choice ultimately depends on what matters most to the buyer.

Are Expensive Diamonds Always Better?

No.

A $1 million diamond isn’t necessarily more beautiful to every person than a $10,000 diamond.

Luxury pricing often reflects extreme rarity.

Consider a rare pink diamond that has an unusual combination of color, clarity and size. Its extraordinary price may be driven by the fact that very few comparable stones exist.

For everyday jewelry, buyers should focus on appearance, quality, certification and personal preference, rather than simply choosing the most expensive stone available.

What Makes a Diamond Rare?

Diamond rarity can come from different sources.

Size rarity

Large diamonds are naturally less common.

Color rarity

Natural red, pink, blue and green diamonds can be exceptionally rare.

Clarity rarity

Large diamonds with extremely high clarity are difficult to find.

Combination rarity

This is perhaps the most important factor for record-breaking stones.

A 1-carat diamond with an unusual color may be rare.

A 10-carat diamond with exceptional color and clarity may be extraordinarily rare.

The combination of several desirable characteristics can create a one-of-a-kind gemstone.

Famous Diamond Colors Ranked by Rarity

There is no universal ranking applicable to every stone, but natural fancy colors are generally not equally common.

Very rare categories include:

Red
Pink
Blue
Green
Purple
Orange
Yellow
Brown

The exact order can vary depending on hue, tone, saturation, size and other characteristics.

GIA specifically notes that red, green, purple and orange are among the rarest fancy colors, while pink and blue are also highly prized.

Best Diamond Shapes

The best diamond shape depends on personal preference.

Round Brilliant

The most classic choice.

Advantages:

Exceptional brilliance
Timeless appearance
Widely available
Easy to match with different settings

Oval

Oval diamonds can provide a larger-looking appearance for their carat weight.

Princess

A square or rectangular shape with modern styling.

Emerald

Known for a sophisticated step-cut appearance.

Cushion

A romantic shape with rounded corners and a vintage feel.

Pear

A combination of round and marquise characteristics.

Marquise

A long shape that can create the appearance of greater finger coverage.

There is no universally “best” shape. The best choice is the one that suits the wearer.

How to Choose the Best Diamond for an Engagement Ring

If you’re buying a diamond engagement ring, start with your budget.

Then prioritize:

Step 1: Decide between natural and lab-grown

This can significantly affect the available size and quality within your budget.

Step 2: Choose the shape

Think about personal style.

Step 3: Prioritize cut

For a traditional round brilliant, cut quality is particularly important.

Step 4: Select color

Choose the highest color grade that fits comfortably within your budget.

Step 5: Choose clarity

Look for a stone that is visually clean rather than automatically paying for the highest grade.

Step 6: Verify certification

Buy from a reputable seller and review the laboratory report.

Step 7: Compare prices

Compare diamonds based on similar specifications instead of comparing only total prices.

Diamond Certification: Why It Matters

A diamond certificate, more accurately called a grading report or laboratory report, provides independent information about the gemstone.

It can include details such as:

Carat weight
Color
Clarity
Cut
Measurements
Proportions
Fluorescence
Diamond identification
Treatment information

For valuable diamonds, independent grading can help buyers make informed decisions.

Always make sure the report corresponds to the actual diamond.

Are Natural Diamonds an Investment?

This is a complicated question.

Some exceptional diamonds have achieved extraordinary auction prices. Rare colored diamonds, especially high-quality pink and blue stones, have attracted major collector demand.

However, consumers should not assume that every diamond will increase in value.

A diamond purchased at retail can have a significant difference between its purchase price and potential resale price.

Investment-grade diamonds are a specialized market.

If your primary goal is investment, professional advice and specialized market knowledge are important.

If your primary goal is jewelry, beauty and personal enjoyment may be more appropriate criteria.

The Future of the Diamond Industry

The diamond industry is changing rapidly.

Laboratory-grown diamonds have expanded consumer choice.

Technology has improved diamond identification.

Online shopping has made price comparison easier.

Consumers are also increasingly interested in provenance and the origin of gemstones.

At the same time, exceptional natural diamonds continue to attract collectors because their geological rarity cannot simply be reproduced by increasing production.

GIA’s recent research highlights continuing developments in laboratory-grown diamond technology, including both CVD and HPHT production and advances in identification methods.

Frequently Asked Questions About the Best Diamonds in the World

What is the best diamond in the world?

There is no single universally accepted best diamond. The answer depends on whether you value size, color, clarity, historical importance, rarity or auction value. Famous examples include the Cullinan, Hope Diamond and CTF Pink Star.

What is the biggest diamond in the world?

The Cullinan is recognized as the largest gem-quality rough diamond discovered, weighing approximately 3,106 carats.

What is the most expensive diamond ever sold?

The CTF Pink Star sold for approximately $71.2 million at Sotheby’s Hong Kong in 2017 and holds the auction record.

What is the rarest diamond color?

Red diamonds are among the rarest, while high-quality pink, blue and green diamonds are also exceptionally rare and valuable.

Are bigger diamonds always more expensive?

No. Size is important, but color, clarity, cut, rarity and provenance can have a major effect on price.

What are the cheapest diamonds?

Smaller natural diamonds, diamonds with lower but acceptable color or clarity grades, and laboratory-grown diamonds can provide more affordable options.

Are lab-grown diamonds real diamonds?

Yes. Laboratory-grown diamonds are diamonds with essentially the same chemical, physical and optical properties as natural diamonds, but they are produced in a laboratory rather than formed naturally in the Earth.

What are the main types of diamonds?

Diamonds can be classified as natural or laboratory-grown, and they can also be categorized by color, crystal characteristics, shape, cut and treatment.

Which diamond color is most expensive?

There is no single answer for every stone, but exceptional pink, blue, green and red diamonds can command extremely high prices. GIA identifies saturated pinks, blues and greens among the most valuable fancy-color categories.

Is a Flawless diamond worth the money?

Not necessarily for every buyer. A lower-clarity diamond can still look beautiful if inclusions are not visible to the naked eye. The right balance of cut, color, clarity and carat depends on your budget.

Final Thoughts: Finding the Best Diamond

The world of diamonds is much bigger than simply choosing the largest or most expensive stone.

The best diamonds in the world represent different forms of rarity.

Some are famous because they are enormous. Some are valuable because they have extraordinary color. Others became legendary because they belonged to royalty or played a role in history.

The Cullinan demonstrates the extraordinary possibilities of size. The Hope Diamond demonstrates the fascination of blue diamonds. The CTF Pink Star demonstrates the extraordinary value of a rare vivid pink diamond. And diamonds such as red, blue, pink and green stones demonstrate how nature can produce gemstones that are extraordinarily difficult to find.

For ordinary buyers, however, the best diamond is not necessarily the biggest, rarest or most expensive.

It is the diamond that offers the right combination of beauty, quality, authenticity and price for the person buying it.

Understanding the types of diamonds, the 4Cs, diamond colors, carat weight, certification and the difference between natural and laboratory-grown diamonds makes it much easier to make a confident decision.

Whether you are researching the biggest diamonds in the world, looking for the largest diamonds, comparing smallest diamonds, exploring expensive and cheaper diamonds, or simply trying to understand the best diamonds in the world, the key lesson is simple:

Diamond value is created by rarity—and rarity is about much more than size.