Geneva Auction to Feature Rare 8.63 Carat Pink Diamond

 

An exceptional 8.63 carat natural pink diamond is set to take centre stage at Sotheby’s High Jewelry auction in Geneva on 11 November 2026, with an estimated price of up to US$6 million. The stone highlights the extraordinary rarity of natural pink diamonds and the continuing fascination they hold for collectors of important gemstones.

The unmounted oval modified brilliant cut diamond has been graded Fancy Intense Pink, VS2 clarity and Type IIa. Sotheby’s will present it as the leading lot in its High Jewelry sale, which will take place immediately before the auction house’s Royal & Noble Jewels sale in Geneva.

The diamond carries an estimated value of CHF 3.3 million to CHF 5 million, equivalent to approximately US$4 million to US$6 million. Its combination of substantial carat weight, intense natural colour and desirable gemological characteristics places it among the notable coloured diamonds appearing at international auction this season.

Where are natural pink diamonds found?

Natural pink diamonds have been recovered from several regions around the world, including Australia, South Africa, Lesotho, Tanzania, Russia, Brazil, Canada and historically India. However, these sources have not contributed equally to the market, and the geological conditions required to produce diamonds with a strong natural pink colour are exceptionally uncommon.

For decades, the most important commercial source was the Argyle diamond mine in Western Australia. Argyle became internationally renowned for its pink and red diamonds, despite these stones representing only a tiny fraction of the mine’s overall diamond production. The mine ceased operations in 2020, bringing an end to the regular supply from the world’s most significant historical source of pink diamonds.

Since the closure, the market has become even more conscious of the finite supply of Argyle-origin stones. However, pink diamonds continue to be found elsewhere, and discoveries in places such as Lesotho demonstrate that the geological potential for exceptional pink diamonds extends beyond Australia.

South Africa has its own distinguished place in this history, having produced some of the most famous large pink diamonds ever discovered.

The Steinmetz Pink: a South African diamond of extraordinary scale

One of the most remarkable examples of South Africa’s contribution to the world of natural pink diamonds is the legendary 59.60 carat Steinmetz Pink, now known as the CTF Pink Star.

The diamond began as a 132.50 carat rough crystal mined by De Beers in Africa in 1999. It was subsequently cut and polished by Steinmetz Diamonds over nearly two years, emerging as an oval diamond graded Fancy Vivid Pink and Internally Flawless by the Gemological Institute of America (GIA). It was unveiled publicly in Monaco in 2003 as the Steinmetz Pink.

The diamond later became known as the Pink Star and, following its acquisition by Hong Kong jewellery group Chow Tai Fook, the CTF Pink Star. In April 2017, it sold at Sotheby’s Hong Kong auction for HK$553 million, approximately US$71.2 million, setting a world auction record for a diamond or gemstone.

Its history illustrates why South Africa remains an important part of the story of exceptional pink diamonds. The country’s historic diamond fields have produced important coloured stones, including diamonds of remarkable size and quality.
Why are some pink diamonds so large?

The size of an exceptional pink diamond is not simply a consequence of its colour. Pink diamonds can occur in different geological environments, and their colour is associated with structural deformation within the diamond’s crystal lattice. This deformation affects how the stone interacts with light, producing its characteristic pink appearance. The precise mechanisms responsible for colour can vary between stones.

South Africa’s historic diamond deposits have produced large, important diamonds, while the Argyle mine in Australia became the dominant commercial source of pink diamonds because of the frequency with which pink stones appeared in its production. These are distinct geological and mining histories, rather than evidence that one country exclusively produces the largest pink diamonds.

The Steinmetz Pink demonstrates what can happen when a substantial rough diamond combines with exceptional colour and clarity. Its finished weight of 59.60 carats is particularly extraordinary because cutting a rough diamond involves balancing the retention of carat weight against the need to maximise colour, clarity, symmetry and overall appearance.

Unlike colourless diamonds, where the absence of colour is a major grading consideration, fancy coloured diamonds are assessed principally for their colour characteristics. These include hue, tone and saturation, alongside the stone’s clarity, carat weight, cut and overall appearance.

The distinction between Fancy Intense Pink and Fancy Vivid Pink is important. Fancy Vivid Pink represents a higher colour-intensity category, but it does not automatically follow that every vivid pink diamond is more valuable than every intense pink diamond. Size, clarity, colour distribution, cutting quality and market demand all influence the final price.

The November Geneva offering is graded Fancy Intense Pink with VS2 clarity. Its 8.63 carat weight and reported Type IIa classification add further gemological interest. Type IIa diamonds contain extremely low levels of nitrogen and can possess exceptional optical properties, although this classification alone does not establish a diamond’s value or geographic origin.

For DCLA, the auction is a reminder of the importance of independent gemological assessment when dealing with exceptional natural coloured diamonds. Reliable identification, colour grading, clarity assessment and documentation are essential to understanding what makes each stone distinctive.

A rare natural treasure in a changing market

The closure of the Argyle mine has brought greater attention to the scarcity of natural pink diamonds, particularly stones with strong colour and significant carat weight. While new discoveries remain possible in other diamond-producing regions, exceptional natural pink diamonds continue to be rare.

The upcoming Sotheby’s Geneva sale will provide another opportunity to see how collectors respond to a remarkable natural coloured diamond. Whether the 8.63 carat stone reaches its upper estimate remains to be seen, but its appearance at auction reinforces the enduring appeal of gemstones whose beauty is the result of extraordinary geological processes.

From South Africa’s famous Steinmetz Pink to the celebrated pink diamonds of Australia’s Argyle mine, these stones represent some of the most remarkable achievements of nature and the skill of the diamond cutter.

For further reading, explore DCLA’s coverage of Boodles and its major Argyle diamond acquisition and the laboratory’s historical report on the 59.60 carat pink diamond’s record-breaking auction.

DCLA is the Diamond Certification Laboratory of Australia. Independent gemological examination and accurate reporting help establish a diamond’s characteristics and support informed understanding of these rare natural treasures.

Inclusion Size Alone Does Not Determine a Diamond's Grade

 

Diamond Science, Grading and Transparency

Introduction

Diamond clarity is often misunderstood as a straightforward measurement of the size of an inclusion relative to the size of the diamond. While inclusion size is an important grading consideration, it is only one component of a more comprehensive gemmological assessment.

Two diamonds containing inclusions of apparently identical size and colour may receive different clarity grades because the inclusions differ in position, nature, contrast and overall visual impact. The diamond’s shape, facet arrangement and optical behaviour can also influence how readily an inclusion is observed.

At the Diamond Certification Laboratory of Australia (DCLA), diamond grading follows established International Diamond Council (IDC) nomenclature and grading principles. DCLA also assesses transparency as a separate characteristic, helping to distinguish the visibility of individual inclusions from the degree to which internal features interfere with light transmission.

Understanding these distinctions is essential when interpreting a diamond grading report and evaluating the relationship between clarity, transparency and overall optical performance.

1. Diamond clarity is more than inclusion size

Diamond clarity describes the internal characteristics, known as inclusions, and external characteristics, known as blemishes, that are observed during examination.

The commonly used clarity scale ranges from Flawless (FL) and Internally Flawless (IF), through the VVS, VS and SI categories, to Included grades. The precise grade depends on the grading system applied and the combined assessment of relevant characteristics.

Although size is important, clarity grading is not determined by a simple calculation of inclusion diameter divided by the diamond’s dimensions. Instead, the grader evaluates the characteristics of the inclusion in the context of the individual stone.

Important considerations include:

• Size: The dimensions and apparent extent of the inclusion.
• Position: Where the inclusion is located within the diamond.
• Nature: The type, shape, structure and visual characteristics of the inclusion.
• Relief and contrast: How distinctly the inclusion stands out against its surrounding optical environment.
• Number and distribution: Whether there is one isolated feature or a number of inclusions distributed throughout the stone.
• Overall effect: The combined influence of these characteristics on the diamond’s appearance under the prescribed grading conditions.

These factors interact. An inclusion that is relatively inconspicuous in one diamond may be considerably more apparent in another, even where their measured dimensions are similar.

For further information, see DCLA’s Diamond Clarity Guide and Four Cs of Diamond Grading.

2. The influence of diamond shape and facet arrangement

The optical behaviour of a diamond is influenced by its cut style, proportions, facet arrangement and the conditions under which it is observed.

A round brilliant diamond has numerous facets arranged to produce characteristic patterns of brightness, contrast and scintillation. These changing patterns can make an inclusion less apparent in some viewing positions while making it more conspicuous in others.

By comparison, a step-cut diamond, such as an emerald cut, generally has larger, elongated facets arranged in parallel rows. This produces a different optical appearance, often described as a hall-of-mirrors effect.

The distinction is important because the same inclusion may appear differently in the two cuts. A small inclusion can be masked by the complex light and dark patterns of a brilliant cut, yet stand out more clearly against the relatively broad facets of a step cut.

However, this is not an absolute rule. An inclusion may be highly visible in a brilliant cut if it creates strong contrast or occupies a prominent position. Likewise, a step-cut diamond may conceal an inclusion under certain viewing conditions.

The relevant principle is that inclusion visibility depends on the interaction between the inclusion and the diamond’s optical environment, not solely on its physical dimensions.

3. Why the position of an inclusion matters

The location of an inclusion can substantially influence its apparent visibility and its contribution to the final clarity grade.

Beneath the table

The table is the large central facet on the crown of a typical brilliant-cut diamond. An inclusion positioned beneath the table may be readily visible when the diamond is viewed face-up, particularly if it is dark, sharply defined or surrounded by a contrasting facet pattern.

A centrally located inclusion is not automatically more serious than one elsewhere. Its actual impact depends on its dimensions, nature, contrast and visibility under grading conditions.

Within the crown region

Inclusions beneath the crown facets may interact with the diamond’s changing patterns of brightness and darkness. Depending on their position and contrast, they may be conspicuous from certain viewing angles and less apparent from others.

At or near the girdle

The girdle is the perimeter separating the crown from the pavilion. An inclusion close to this region may be less apparent when the diamond is viewed face-up, depending on its depth, orientation and relationship to the surrounding facets.

Some inclusions near the girdle may nevertheless be readily visible from the side or at particular viewing angles. Their location does not automatically justify a higher or lower clarity grade.

Within the pavilion

The pavilion is the lower portion of the diamond beneath the girdle. Inclusions located in this region can interact with reflected light and facet patterns in complex ways.

A pavilion inclusion may appear to have multiple visual counterparts because of internal reflections. These apparent repetitions are optical effects rather than necessarily separate inclusions.

The visibility of a pavilion inclusion therefore depends on its location, orientation, contrast and the optical behaviour of the stone.

At the culet

The culet is the small facet, or point where no culet facet is present, at the bottom of the diamond. An inclusion or other characteristic in this region may be influenced by the surrounding pavilion facets and viewing angle.

As with other positions, its contribution to clarity must be assessed in the context of the complete diamond.

These examples demonstrate why location is a significant part of clarity grading, but cannot be evaluated independently of the other grading factors.

For terminology relating to diamond structure and facet arrangement, consult the DCLA Diamond Glossary and Picture Library.

4. The nature of an inclusion

The term inclusion covers a broad range of internal features. Their appearance and optical effect can vary substantially, even when their dimensions are similar.

Dark mineral or crystal inclusions

Dark inclusions may create strong visual contrast against a bright facet. Their apparent prominence depends on their size, location, shape and the lighting and viewing conditions.

Light or colourless inclusions

Some inclusions are relatively light in appearance and may blend into their surroundings. Others become conspicuous when positioned against a dark facet or when their boundaries scatter or interrupt light.

Clouds

A cloud is a grouping of very small inclusions that may collectively create a hazy or diffuse appearance. Individual components can be difficult to resolve, particularly at lower magnification, while their combined effect may be more apparent.

The grading significance of a cloud depends on its density, distribution, extent and visual effect.

Pinpoints and minute crystals

Very small inclusions may be difficult to identify individually. When present in groups, however, they can contribute to a cloud-like appearance or affect the diamond’s overall visual character.

Internal graining and twinning wisps

Internal graining may appear as lines or bands associated with irregularities in the diamond’s crystal structure. Twinning wisps are a particular type of internal feature associated with twinning planes and may appear as fine, thread-like or cloud-like patterns.

These characteristics should not be confused with a simple description of unbonded carbon. Their precise nature must be established through appropriate gemmological examination.

Feathers and fractures

A feather is a feather-like internal fracture or break, often with a light appearance under certain viewing conditions. In the diamond trade, the term gletz is also used for certain fracture-like features.

The significance of a feather depends on its size, position, visibility and other characteristics. Its potential effect on durability is a separate consideration from its contribution to clarity grading.

The DCLA Diamond Clarity Guide provides further information about clarity characteristics and their role in grading.

5. Contrast: Why some inclusions are more visible than others

Contrast is an important consideration when evaluating the apparent visibility of an inclusion.

A well-cut diamond viewed face-up naturally displays alternating bright and dark areas. These patterns are part of its optical behaviour and are influenced by the diamond’s facet arrangement, proportions, lighting and viewing position.

An inclusion that appears dark against a bright facet may be particularly conspicuous. Similarly, a light inclusion against a dark facet can produce strong contrast and become readily identifiable.

Conversely, an inclusion may be less apparent when its appearance closely resembles that of the surrounding area.

Consider a hypothetical example: a dark inclusion in a diamond initially assessed as VS2 may become sufficiently prominent under the applicable grading conditions to support an SI1 grade. Conversely, a less conspicuous inclusion in a different position may have a smaller effect on the final assessment.

These examples are illustrative, not automatic grading rules. A grade cannot be changed solely because an inclusion is black, white, central or close to the girdle. The complete set of grading criteria must be considered.

This is one reason clarity grading requires trained observation and consistent application of established standards rather than a simple measurement of inclusion size.

6. Clouds and the distinction between clarity and transparency

An important distinction in diamond assessment is the difference between clarity and transparency.

Clarity evaluates the diamond’s internal and external characteristics according to the relevant grading methodology.

Transparency concerns the degree to which light can pass through the material without significant obstruction, haze or cloudiness.

A diamond can have a recognised clarity grade yet exhibit a degree of internal cloudiness that affects its transparency. Conversely, a diamond containing inclusions may still display very good or excellent transparency.

For example, a diamond graded VS2 may contain a dispersed cloud of microscopic features. Depending on the cloud’s density, distribution and optical effect, the stone may show a degree of haze even though individual inclusions are difficult to distinguish.

The relationship is not automatic: a cloud does not necessarily reduce transparency, and a lower clarity grade does not necessarily indicate poor transparency.

Magnification and lighting can also change how internal features are observed. A cloud may be difficult to resolve as separate inclusions under a standard 10× loupe yet appear more evident under a microscope or under particular illumination. This does not, by itself, establish a lower clarity grade. The grading assessment must follow the relevant examination procedure.

The important point is that clarity and transparency describe related but different properties. Neither should be used as a substitute for the other.

7. The DCLA Transparency Grading System

DCLA developed its Transparency Grading System to provide additional information about a diamond’s optical characteristics beyond its conventional quality grades.

The system assesses the degree of transparency and the extent to which haze, cloudiness or other internal features interfere with light transmission. This information can help distinguish between diamonds that share a similar clarity grade but have different transparency characteristics.

DCLA’s published transparency scale comprises five categories:

• Excellent: Completely transparent, with no significant haze or cloud affecting transparency.
• Very Good: Transparent, with minimal light interruption and only very slight haze or cloud.
• Good: Transparent, with slight detectable haze or cloud.
• Medium: Semi-transparent, with marked light interruption and more readily detectable haze or cloud.
• Poor: Semi-transparent, with substantial haze or cloud and very limited light transmission.

The assessment of transparency complements rather than replaces clarity grading. It offers additional context for understanding a diamond’s visual performance.

For the background to this approach, read DCLA’s Transparency Grading System.

8. Cut, brilliance and the overall assessment of a diamond

Clarity is only one aspect of diamond quality. The diamond’s cut and proportions influence how light interacts with its facets and contributes to its visual appearance.

Brilliance describes the return of white light, while fire refers to the dispersion of white light into spectral colours. Scintillation describes the flashes of light and dark that occur as the diamond, light source or observer moves.

These optical effects are influenced by cut quality, proportions, symmetry, polish and viewing conditions. Internal characteristics can also affect appearance, but clarity alone does not determine a diamond’s brilliance or fire.

A diamond with a high clarity grade may still have limited optical performance if its proportions or facet arrangement are unfavourable. Similarly, a diamond with a lower clarity grade may exhibit attractive brilliance and fire if its cut and transparency are favourable.

For this reason, a complete assessment should consider the diamond’s relevant characteristics together rather than treating any single grade as a definitive measure of overall beauty.

DCLA’s Diamond Grading Process explains the laboratory’s assessment of weight, measurements, colour, clarity, cut, polish, symmetry and transparency.

Conclusion: Understanding the complete diamond

Diamond clarity is a multifactorial assessment. Inclusion size matters, but its significance depends on the feature’s position, nature, contrast, number and distribution, together with the applicable grading methodology.

The optical characteristics of the diamond influence how inclusions appear, while clouds and other microscopic features may affect transparency in ways that are not fully expressed by a clarity grade alone.

DCLA’s approach recognises the value of assessing these characteristics separately. By combining conventional diamond grading with an additional transparency assessment, the laboratory provides a more comprehensive description of the stone.

For jewellers, diamond professionals and consumers, understanding the difference between clarity and transparency helps create a more informed interpretation of a diamond grading report.

Explore more diamond education resources: Diamond Clarity | Four Cs of Diamond Grading | Diamond Grading Reports | Diamond Glossary and Picture Library

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DCLA Diamond Glossary: Clarity and Transparency

The following glossary can accompany this article and link readers to relevant entries in the DCLA Diamond Glossary and Picture Library.

Blemish: An external characteristic or mark on the surface of a polished diamond.

Brilliance: The appearance of white light returned by a diamond.

Cloud: A grouping of minute inclusions that may collectively create a diffuse or hazy appearance.

Clarity: The assessment of a diamond’s internal inclusions and external blemishes under the applicable grading methodology.

Contrast: The visual difference between an inclusion and its surrounding optical environment, which can influence its apparent visibility.

Crown: The upper portion of a polished diamond, extending from the girdle to the table.

Culet: The small facet, or point where no culet facet is present, at the bottom of a diamond.

Facet: A polished, flat surface on a cut diamond.

Feather: A feather-like internal fracture or break within a diamond.

Fire: The dispersion of white light into spectral colours as it passes through a diamond.

Girdle: The perimeter of a polished diamond separating the crown from the pavilion.

Inclusion: An internal characteristic within a diamond, such as a crystal, cloud, feather or internal graining feature.

Pavilion: The lower portion of a polished diamond, extending from the girdle towards the culet.

Scintillation: The flashes of light and dark observed as a diamond, light source or observer moves.

Step cut: A cutting style characterised by rows of elongated facets, commonly found in emerald-cut diamonds.

Table: The large upper facet of a typical brilliant-cut diamond.

Transparency: The degree to which light passes through a diamond without significant obstruction from haze, cloudiness or other internal features.

Twinning wisps: Fine, thread-like or cloud-like internal features associated with twinning planes within the diamond’s crystal structure.

VVS, VS, SI and Included: Categories within commonly used diamond clarity grading scales, representing different levels of inclusion visibility and significance under the applicable grading criteria.

Related DCLA resources

• Diamond Clarity Guide
• Diamond Grading Process
• DCLA Transparency Grading System
• Diamond Glossary and Picture Library
• Diamond Grading Report

Does Adding Diamonds to a Luxury Watch Increase Its Value or Reduce It?

 

When diamonds meet fine watchmaking, is more always worth more?

A luxury watch is much more than a timekeeping instrument. For collectors, it represents precision engineering, heritage, craftsmanship and, in some cases, a significant store of value. Brands such as Rolex, Patek Philippe and Audemars Piguet have built their reputations over generations, with certain models becoming highly sought after by collectors around the world.

It is understandable that an owner might want to personalise a luxury watch by adding diamonds or coloured gemstones to its bezel, dial, bracelet or case. The result can be visually striking, but does it increase the watch’s market value?

A watch that looks more luxurious is not necessarily worth more.

The answer depends on the watch, the quality of the modification, its originality and, most importantly, what future buyers are prepared to pay for it.

1. Do diamonds increase the value of a luxury watch?

The first distinction is between a watch originally manufactured with factory-set diamonds and one modified later by an independent jeweller.

Although the two watches may look similar, collectors and specialist watch dealers can regard them very differently.

Factory-set diamonds

When a manufacturer offers a diamond-set model, the gemstones are selected, set and finished as part of the original production process. The setting is designed around the watch, and the finished piece forms part of the manufacturer’s specifications.

The stones, craftsmanship, model reference, rarity and original documentation all contribute to the watch’s identity.

Certain factory-set Rolex Day-Date and Datejust models, diamond-set Patek Philippe watches and gem-set Audemars Piguet Royal Oak models are desirable in their own right. However, factory-set diamonds do not automatically guarantee a higher resale price. The particular model, condition, originality and market demand remain important.

Aftermarket diamonds and gemstones

An aftermarket modification occurs when diamonds or other gemstones are added after the watch leaves the manufacturer, usually by an independent jeweller or specialist customisation company.

Although the stones themselves may have genuine monetary value, the cost of the materials and workmanship is not necessarily reflected in the resale price of the finished watch.

Consider a hypothetical example.

An owner purchases a luxury watch for $30,000 and spends another $10,000 having diamonds added to the bezel and bracelet. The total expenditure is now $40,000, but this does not mean the modified watch will sell for $40,000 or more.

A prospective buyer may prefer the original watch, question the quality of the setting or simply be unwilling to pay extra for a design that does not reflect the manufacturer’s specifications.

The modification may appeal to a particular buyer who appreciates the appearance. However, it can also reduce the pool of potential buyers.

The value of the diamonds and the value of the watch are two separate considerations.

A qualified gemmologist can assess the gemstones independently, but that assessment does not establish the resale value of the complete watch.

2. Will Rolex service a modified watch?

This is one of the most important questions to consider before making any alterations.

Rolex has established a global reputation for precision, reliability, durability and consistent manufacturing standards. Its watches are designed and tested as complete products, with cases, bezels, dials, bracelets and movements engineered to work together.

When an independent jeweller adds diamonds or changes original components, several issues may arise.

Rolex’s official servicing process involves a technical and aesthetic assessment of the watch. The company examines its components, services the movement as required and conducts tests that include checking water resistance and timekeeping performance.

Alterations by unauthorised third parties can affect the manufacturer’s warranty and may influence whether a watch is accepted for particular servicing work.

An aftermarket diamond bezel, modified dial or altered bracelet may create difficulties if the watch no longer meets the manufacturer’s specifications. Depending on the watch and the nature of the alteration, the service centre may require the watch to be returned to an acceptable original configuration or may decline certain work.

It is important to distinguish between a watch being accepted for assessment, being eligible for a particular repair and being eligible for a complete official service. These are not necessarily the same thing.

Owners should contact an authorised Rolex retailer or service centre before modifying their watch rather than assuming that future servicing will remain unaffected.

For a valuable or collectible Rolex, preserving the original components and configuration is generally the more conservative approach.

The same principle applies to other prestigious manufacturers, including Patek Philippe and Audemars Piguet. Each has its own service requirements and policies, so owners should seek confirmation directly from the relevant manufacturer.

3. How modifications can affect future resale value

The secondary market for luxury watches is influenced by several factors beyond the original purchase price.

These include:

• Originality: Collectors often favour watches that retain their original manufacturer-specified components.
• Model and reference: Some models have a much stronger collector following than others.
• Condition: Damage, poor workmanship, excessive polishing or changes to the case can affect desirability.
• Provenance: Original paperwork, service records, purchase history and matching components can help establish authenticity and history.
• Manufacturer support: Confidence in future servicing can influence a buyer’s decision.
• Market demand: A customised design may appeal strongly to one buyer while discouraging many others.

A modification can therefore have three broad outcomes.

It may add value to a specific buyer. Someone seeking a distinctive, diamond-encrusted watch may be prepared to pay a premium for its appearance.

It may have little effect on value. The buyer may consider the stones an additional feature but place most of the value on the underlying watch.

It may reduce value. Collectors seeking an original example may avoid the watch, particularly when the modification affects important original components or creates uncertainty about servicing.

The financial risk is that the owner pays for the customisation but cannot recover the cost when selling.

For watches with strong collector demand, preserving originality may be more valuable in the long term than adding decorative features.

There are exceptions. Some historical watches with unusual modifications, bespoke commissions or documented provenance can become highly desirable. However, these exceptional cases should not be treated as a general rule for modern luxury watches.

4. What about coloured gemstones?

Diamonds are not the only stones used to customise luxury watches. Sapphires, rubies and emeralds can be incorporated into bezels, hour markers and other decorative elements.

From a gemmological perspective, their value depends on factors such as natural or laboratory-grown origin, colour, clarity, treatment, carat weight and cutting quality. For certain stones, origin and the presence or absence of treatments can also have a substantial effect on value.

However, the same principle applies: a valuable gemstone does not automatically increase the value of the watch into which it has been set.

The setting method matters as well. Drilling, cutting, removing or replacing original components can permanently alter the watch. Poorly executed work may damage the metal, compromise the fit of components or affect the integrity of the case.

Water resistance is another consideration. A watch designed for a particular level of water resistance should not be assumed to retain that performance following modification.

Before any work begins, owners should establish whether the proposed design can be completed without compromising the watch’s construction or future serviceability.

5. The world’s leading high-end watchmakers

To understand why originality matters, it helps to appreciate the history and identity of the leading names in fine watchmaking. These manufacturers are not simply selling precious metals and gemstones. They are selling design, engineering, heritage and reputations built over generations.

1. Rolex

Founded in 1905 by Hans Wilsdorf and Alfred Davis in London, Rolex moved its operations to Geneva in 1919. The company became synonymous with robust, precise and dependable wristwatches.

Milestones include the Oyster waterproof case introduced in 1926 and the Perpetual self-winding rotor system introduced in 1931.

Iconic collections include the Submariner, Daytona, Datejust, Day-Date and GMT-Master.

Rolex enjoys enormous global recognition, but its watches are not all equally collectible. Originality, reference, rarity and condition remain important when assessing resale value.

Official website: https://www.rolex.com/

2. Audemars Piguet

Established in 1875 by Jules Louis Audemars and Edward Auguste Piguet in Le Brassus, Switzerland, Audemars Piguet is one of the great independent names in Swiss haute horlogerie, or high watchmaking.

Its defining moment came in 1972 with the introduction of the Royal Oak, designed by Gérald Genta. Its exposed screws, octagonal bezel and integrated bracelet challenged the convention that luxury watches should be made primarily from gold or platinum.

The use of stainless steel in a high-end sports watch helped create an entirely new luxury category.

Today, the Royal Oak and Royal Oak Offshore are among the brand’s best-known collections. Because design details and originality are central to their appeal, modifying a desirable example warrants particular care.

Official website: https://www.audemarspiguet.com/

3. Patek Philippe

Founded in Geneva in 1839 by Antoni Patek and Adrien Philippe, Patek Philippe is among the most prestigious names in traditional watchmaking.

The company is celebrated for intricate mechanical movements, perpetual calendars, minute repeaters and other sophisticated complications.

Its notable collections include the Calatrava, Nautilus, Aquanaut and Grand Complications. Certain rare Patek Philippe watches have achieved extraordinary results at international auctions.

The brand’s emphasis on craftsmanship, provenance and continuity across generations makes originality particularly relevant to collectors. An aftermarket modification can make an otherwise desirable reference less attractive to buyers seeking a watch that retains its intended factory specification.

Official website: https://www.patek.com/

4. Vacheron Constantin

Founded in Geneva in 1755, Vacheron Constantin is widely recognised as the oldest watch manufacturer with an uninterrupted history of production.

It is renowned for elegant designs, elaborate complications, hand finishing and exceptional craftsmanship.

Its Overseas, Patrimony and Traditionnelle collections range from luxury sports watches to traditional dress watches. Its long history and specialist production make it a major name among serious collectors.

Official website: https://www.vacheron-constantin.com/

5. A. Lange & Söhne

Founded in 1845 in Glashütte, Germany, A. Lange & Söhne represents the finest tradition of German mechanical watchmaking.

After the disruption of the Second World War and the division of Germany, the brand was revived in 1990 by Walter Lange.

Its Lange 1, Datograph and Zeitwerk collections are admired for distinctive design, intricate movements and meticulous finishing. The company attracts collectors who value technical sophistication and traditional craftsmanship.

Official website: https://www.alange-soehne.com/

6. Jaeger-LeCoultre

Founded in 1833 in Le Sentier, Switzerland, Jaeger-LeCoultre is known for technical innovation and in-house movements.

The Reverso, created in 1931 with a case that flips over, is one of the most recognisable designs in horology.

Its Master and Duomètre collections demonstrate the company’s expertise in complicated movements. The brand’s historical designs and engineering are important components of its identity.

Official website: https://www.jaeger-lecoultre.com/

7. Breguet

Founded in 1775 by Abraham-Louis Breguet, the company is associated with some of the most influential developments in mechanical watchmaking.

Abraham-Louis Breguet is credited with inventing the tourbillon, patented in 1801. The brand also became known for distinctive guilloché dials, elegant hands and refined case designs.

Its Classique, Marine and Tradition collections continue to reflect this historic identity.

Official website: https://www.breguet.com/

8. Blancpain

Founded in 1735, Blancpain is one of Switzerland’s historic watch brands and is closely associated with traditional mechanical watchmaking.

Its Fifty Fathoms, introduced in 1953, became a landmark in the development of modern dive watches.

The company is also known for sophisticated complications and its Villeret collection. Its heritage appeals to collectors interested in mechanical craftsmanship and specialist watch history.

Official website: https://www.blancpain.com/

9. Richard Mille

Founded in 2001, Richard Mille takes a contemporary approach to high-end watchmaking, using advanced materials, lightweight construction and highly technical movement designs.

Its distinctive tonneau-shaped cases and limited production have made the brand recognisable among luxury watch buyers.

Its comparatively recent history illustrates that prestige can be built through innovation and a strong design identity as well as centuries of tradition.

Official website: https://www.richardmille.com/

10. Cartier

Founded in Paris in 1847, Cartier occupies a distinctive position at the intersection of fine jewellery and watchmaking.

The Santos, developed in the early twentieth century, and the Tank, introduced in 1917, became enduring design icons.

Cartier is especially relevant to the relationship between watches and gemstones because jewellery craftsmanship is central to its heritage. Nevertheless, an original factory-set Cartier watch and an independently modified example can have very different appeal in the secondary market.

Official website: https://www.cartier.com/

Other notable high-end watchmakers

Other important names in fine watchmaking include:

• F.P. Journe: Independent watchmaking, distinctive movements and limited production.
• Greubel Forsey: Highly elaborate mechanisms and exceptional hand finishing.
• H. Moser & Cie.: Refined minimalism, distinctive dials and in-house movements.
• Parmigiani Fleurier: Traditional craftsmanship and sophisticated complications.
• Chopard: Luxury jewellery alongside its L.U.C. mechanical watchmaking collection.
• Piaget: Ultra-thin movements and gem-set luxury designs.
• Harry Winston: Exceptional gemstones and high jewellery, alongside elaborate timepieces.
• Grand Seiko: Precision, distinctive dial finishing and Japanese craftsmanship.
• IWC Schaffhausen: Engineering-led designs, pilot watches and the Portugieser collection.
• Omega: Historic associations with space exploration, Olympic timekeeping, and the Seamaster and Speedmaster collections.
• Zenith: Known for the El Primero high-frequency automatic chronograph.
• Bulgari: Combines Italian design with advanced Swiss watchmaking, notably in the Octo Finissimo range.
• Hublot: Contemporary designs and combinations of unconventional materials.

These brands occupy different positions in the market. Not every model from a prestigious manufacturer is rare or appreciates in value, and there is no universal ranking that determines future resale performance.

6. Why factory originality matters to collectors

One of the most important lessons in both the diamond and luxury watch markets is that quality and originality are not the same thing.

A beautifully cut diamond can be valuable. A finely crafted watch can be valuable. But combining the two does not automatically create an object worth more than the sum of its parts.

Manufacturers such as Rolex and Patek Philippe have built their reputations on carefully controlled production standards. Their servicing and restoration processes are designed to maintain the technical and aesthetic integrity of their watches.

For collectors, an alteration may introduce uncertainty about:

• Whether the original bezel, dial or bracelet has been replaced.
• Whether the gemstones were set without damaging the original components.
• Whether the watch can still be serviced by the manufacturer.
• Whether the watch retains its original specifications and provenance.
• Whether a future buyer will regard the modification as desirable.

These concerns can influence the price a buyer is willing to offer, even when the added diamonds are of excellent quality.

7. What should you consider before modifying a luxury watch?

If you own a Rolex, Audemars Piguet, Patek Philippe or another high-end timepiece, consider the following before authorising any diamond or gemstone work.

Contact the manufacturer first. Ask whether the proposed modification will affect warranty coverage, official servicing or eligibility for repairs.

Obtain an independent valuation. Establish the watch’s current market value before spending money on alterations. For a rare or collectible watch, seek advice from a specialist who understands its exact reference.

Document the gemstones. Keep invoices and obtain appropriate gemmological documentation where warranted. Record whether the stones are natural or laboratory-grown, together with relevant quality characteristics and any treatments.

Preserve all original components. Keep the original bezel, dial, bracelet and other removed parts, along with the box, papers, receipts and service records. These may be important if the watch is later restored or sold.

Consider the eventual buyer. If resale is important, ask an independent specialist how the proposed work is likely to affect demand. The cost of customisation should never be assumed to translate directly into additional resale value.

8. The DCLA perspective: understanding the value of diamonds

At the Diamond Certification Laboratory of Australia (DCLA), we recognise that diamonds and fine jewellery can carry considerable financial and sentimental value. Understanding what you own is an important part of making informed decisions about its future.

When diamonds are incorporated into a luxury watch, several separate questions need to be answered:

1. Are the gemstones natural or laboratory-grown?
2. What is their quality, and are there treatments that affect their value?
3. Is the setting workmanship of an appropriate standard?
4. Has the modification affected the integrity or originality of the watch?
5. What is the market value of the complete watch in its current condition?

These are different questions and may require different specialists.

A gemmological report can help establish the characteristics of a diamond, but it is not automatically a valuation of the stone, the watch or the complete customised item. Likewise, a watch valuation must take account of the manufacturer, model, reference, condition, provenance and current market demand.

For a high-value piece, it may be appropriate to obtain both an independent gemmological assessment and a specialist watch valuation.

Final thoughts: personalise your watch or preserve its value?

Adding diamonds to a luxury watch can produce a striking piece of jewellery, and there is nothing wrong with personalising a watch for your own enjoyment. The important consideration is whether you are doing so for personal satisfaction or with the expectation of increasing its financial value.

If you intend to wear the watch for years and have no intention of selling it, personal preference may be the deciding factor.

If you own a collectible Rolex, Audemars Piguet or Patek Philippe, however, modifying the original design could reduce its appeal to future buyers and complicate servicing. The added gemstones may have genuine value, but that does not mean the overall watch will command a higher price.

Before changing a luxury watch, understand the value of what you already own. A modification that looks more expensive is not necessarily worth more.

At DCLA, we encourage owners to understand the quality, authenticity and value of their diamonds and jewellery before making decisions that could affect their long-term worth.

Disclaimer: This article is intended for general educational purposes and is not financial advice or a formal valuation. Watch servicing policies, warranty conditions and secondary-market values vary by manufacturer, model and circumstances. Contact the relevant manufacturer or authorised service centre before modifying a watch, and consult qualified specialists for individual assessments.

References and further reading

• Rolex — Official servicing procedure: https://www.rolex.com/en-au/watch-care-and-service/the-rolex-servicing-procedure
• Rolex — Official watch care and service FAQs: https://www.rolex.com/en-au/watch-care-and-service/faq
• Patek Philippe — Service and restoration: https://www.patek.com/en/service/our-commitment-to-service/our-commitment-to-service
• Audemars Piguet — Official heritage: https://www.audemarspiguet.com/com/en/about/origins.html
• Vacheron Constantin — History and heritage: https://www.vacheron-constantin.com/au/en/maison/heritage/the-hour-lounge.html
• Christie’s — A collector’s guide to leading luxury watch brands: https://www.christies.com/en/stories/top-luxury-watch-brands-guide-d570d0b7e3fc4bcf8c0957e4ae058a7b

DCLA — Diamond Certification Laboratory of Australia