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Laboratory diamonds - production, properties and trends

Lab-grown diamonds with laser inscription

We cover the following topics in this article:

Jewellery design and the trend towards sustainability

Natural and laboratory diamonds compared

Personal stories and testimonials
What are laboratory diamonds?
Differences to natural diamonds

How jewellers recognise differences
Production of laboratory diamonds
High-pressure, high-temperature process

Chemical vapour deposition

Advantages and disadvantages of HPHT/CVD
Historical development of laboratory methods
Advantages and disadvantages laboratory vs. nature

Environmental friendliness and sustainability

Price development, quality and purity
Purchasing advice for laboratory diamonds

Certifications and quality labels

Price comparison
Conclusion and forecast

In recent years, laboratory diamonds have established themselves as a popular alternative to natural diamonds. Man-made gemstones offer a high-quality alternative to natural diamonds and are significantly cheaper.

A beautiful ring with a 1 ct. diamond that is top quality currently costs around 5,500 euros. A comparable engagement ring with a 1 ct. lab diamond is already available for around 1,200 euros, i.e. for a fifth of the price.

Let's explore the world of engagement rings with laboratory diamonds, their production, advantages and disadvantages. Useful buying tips to help you decide whether to buy a lab-grown diamond.

Jewellery design and the trend towards sustainability

Engagement rings with laboratory diamonds are in no way inferior in design to classic diamond engagement rings. In addition to the familiar settings and cuts, laboratory diamonds sparkle with an almost unlimited choice of colours.

Laboratories can produce diamonds in different colours on request. Blue, yellow or pink stones give the ring a personal touch.

Sustainability is the trend and so more and more couples are opting for laboratory diamonds. Whether these are really more sustainable is still controversial.

Some studies show that man-made diamonds are less harmful to the environment. They are also preferable from an ethical point of view.

Other studies criticise the high energy consumption and the loss of jobs posed by growing diamonds in the lab. In the world's poorer regions in particular, many people make their living from the diamond industry.

It is clear that laboratory-produced diamonds are identical to natural diamonds at the atomic level and even surpass significantly in terms of colour variety.

Natural and laboratory diamonds compared

Laboratory-produced diamonds have the same chemical, optical and physical properties and the same crystal structure as natural diamonds. Natural diamonds and their laboratory-made counterparts both consist of tightly bonded carbon. They are equally hard and both refract light in the same way.

Origin and production

The only relevant difference between laboratory-grown and natural diamonds – apart from the price – is their origin.

This comparison sums it up: lab-grown diamonds are like ice from the freezer, natural diamonds are like glacier ice that is thousands of years old. One is new and man-made, the other was created long ago without human involvement. But both consist of frozen water.

Natural diamonds were formed eons ago deep in the earth under high pressure. Nature formed them and transported them to the earth's surface along with the surrounding kimberlite rock.

Almost all diamonds have impurities inside them as a result of how they were formed. These inclusions and the traces of their growth are what make natural diamonds unique.

Today, laboratory diamonds can be produced in large quantities with very high purity. Depending on the process, there are no or hardly any inclusions in the laboratory. They are produced in a controlled laboratory environment, either in a high-pressure, high-temperature process (HPHT) or by chemical vapour deposition (CVD).

Quality, properties and costs

In the case of natural diamonds, each stone is unique and has individual inclusions and colour nuances. These individual characteristics can be evaluated according to strict criteria, the 4 Cs: Carat (weight), Cut (cut), Colour and Clarity (purity).

Although laboratory-produced diamonds are chemically and physically identical, the spectrum of quality in these diamonds is significantly narrower. Although inclusions cannot be avoided even in the laboratory, they occur much less frequently than in naturally grown diamonds.

Natural diamonds are expensive, primarily due to their rarity, but also because of the complex mining process. Their price varies greatly depending on size, quality and origin.

Laboratory diamonds grow reliably, efficiently and predictably in just a few days. This is particularly noticeable in the price of larger stones, which are considerably cheaper.

Labordiamanten-Zertifikat

Buying engagement rings with lab diamonds

Natural diamonds are considered the traditional gemstones when it comes to engagement rings. They have been classic symbols worldwide of eternal love and constancy for almost a hundred years.

Their rare occurrence leads to high price stability and in the past even to constant increases in value. For many couples, this makes them the clear favourite when it comes to the perfect gemstone for engagement rings.

The prices for the production of industrially manufactured diamonds are at an all-time low. Therefore, lab-grown diamonds are becoming more and more attractive for engagement rings, especially for those with large stones.

These cost only about twenty per cent of the price of high-quality natural diamonds, and are just as brilliant and beautiful. The low price means that couples can choose larger or higher-quality stones without breaking the budget.

Both types of diamond have their advantages. The choice between natural and manufactured diamonds depends on personal values, budget and aesthetic preferences. While some value natural diamonds for their uniqueness and rarity, others favour laboratory diamonds as a sustainable and inexpensive alternative. And all without compromising on quality.

Natural diamonds are considered the traditional gemstones when it comes to engagement rings. They have been classic symbols worldwide of eternal love and constancy for almost a hundred years.

Personal stories and testimonials

„We deliberately chose a fair diamond created with green electricity.“
Sarah and Tom Krawczyk's personal experience

Sarah and Tom had been a couple since 2018 and he decided to propose to her at the end of 2023. He knew that Sarah believed strongly in sustainability and was committed to protecting the environment. That's why he opted for an engagement ring with laboratory diamonds. When he presented her with the ring on Christmas Eve, Sarah was overwhelmed. She instantly loved this jewellery set with diamonds that sparkled romantically in the candlelight.

The fact that it was a stone made with green electricity produced under fair conditions was particularly touching to her. The ring was not only a symbol of their love, but also a sign of the values she and Tom shared.

Testimonial from Lisa Schmied
Augsburg, 24 May 2024

„The stone is breathtakingly beautiful and sparkles just like a natural diamond. We both liked it straight away and we are still completely happy.

I get compliments on my ring all the time and I love how surprised people are when I say it's a lab diamond. I see this ring and I like to think our children can enjoy their future on this beautiful planet because of our choices.

The stone is breathtakingly beautiful and sparkles just like a natural diamond. We both liked it straight away and we are still completely happy.“

Testimonial from Michael P.
Hildesheim, 7 November 2023

"Even before planning the proposal, it was clear that I had to find a special ring. My wife is a sucker for ostentatious jewellery. After extensive research, I therefore decided in favour of an engagement ring with a laboratory diamond.

My wife loves her ring more than anything and practically never takes it off. I am happy with my choice and would recommend it to anyone, although I could get the stone much cheaper today"

What are laboratory diamonds? A definition

Lab-grown diamonds (LGD) are also known as synthetic, cultured, man-made, artificial or cultured diamonds. They are real gemstones that grow within a few days or weeks in a human-controlled laboratory environment.

Experts use two technologies for making them, the high-pressure high-temperature process (HPHT) or chemical vapour deposition (CVD).

Chemically and physically, they are identical to natural diamonds. They consist of pure carbon that crystallises in an isotropic form. Crystals are isotopes if they exhibit the same optical behaviour in every crystallographic direction. As a result, they reflect light evenly.

Differences to natural diamonds

Only rarely does a gemologist recognise CVD- or HPHT-grown diamonds using conventional gemstone testers. State-of-the-art scientific instruments are required for recognising a natural diamond from a lab-grown one. With their help, experts can recognise the difference primarily by deformation patterns, mineral inclusions, fluorescence and other aspects typical of gemstones. Here are the most important ones:

1. Inclusions and structures

Natural diamonds show unique inclusions and structures that are created by geological processes during growth. Although artificial diamonds also have flaws, they are more uniform and less complex.

2. Fluorescence

Lab-grown diamonds fluoresce in characteristic colours with varying degrees of intensity. The type and intensity of the fluorescence distinguishes them from natural diamonds.

3. Analysis with the aid of spectroscopy

Gemmologists use devices such as Raman or infrared spectroscopes to recognise differences in the atomic structure and inclusions.

4. Laser inscriptions

Artificial diamonds from reliable sources have a laser inscription on the girdle that is invisible to the human eye. This is considered proof of their origin from the laboratory.

5. Distinguishing imitations from the original

Imitations such as cubic zirconia or synthetic moissanite, which resemble diamonds, have different chemical and physical properties to diamonds cultivated in the laboratory. These enable trained gemmologists to easily distinguish imitations from genuine diamonds. This is much more difficult with laboratory diamonds.

Wachstumsstrukturen beim natürlichen Diamanten
Growth structures in natural diamonds, known as trigons Growth structures in natural diamonds, known as trigons

How jewellers can spot differences on premises

There are compact devices for jewellers and retailers to distinguish natural diamonds from lab-grown diamonds and imitations. The latest generation of these technological wonders now only require a few seconds to analyse.

If the results of a stone are inconclusive, a test is carried out in the laboratory. If the gemmologist establishes that it is a lab-grown diamond, they will issue a corresponding certificate and mark the stone as lab-grown using laser engraving.

There are now extensive databases worldwide that contain the typical properties of many different types of diamonds. This knowledge helps to develop new methods for identifying natural and artificial diamonds.

Production of laboratory diamonds

It seems like a miracle and lasts only a few days: a tiny natural diamond as a seed is all that is needed for an artificial diamond to grow around it in the laboratory in no time at all. This cultured diamond has amazing properties and – if given a little more time – an impressive size.

In the mid-1950s, scientists grew diamonds in a laboratory for the first time. However, these diamonds were still too small for jewellery. The production of larger gemstone-quality crystals was achieved in the mid-1990s. More and more companies are now producing synthetic diamonds.

The stones from the laboratory are mainly cultivated in China (45%), India (20%) and the USA (10%). Only a small proportion of the production are diamonds in gemstone quality, over 90 per cent are used in industrial applications. The extremely hard material is used for polishing, cutting or removing materials. Synthetic diamonds are used in optical instruments as lenses and in electronics, among other things, or serve as heat conductors.

There are two common methods for producing artificial diamonds: the high-pressure high-temperature process (HPHT) and chemical vapour deposition (CVD).

High-pressure high-temperature process (HPHT)

In this process, the laboratory staff expose a seed diamond to high pressure and extreme heat. The conditions are similar to those under which natural diamonds are formed in the earth.

Diamond growth in the high-pressure, high-temperature process takes place at a pressure of 50,000 to 60,000 bar. This is roughly equivalent to the pressure an elephant would exert on the tip of a needle if it were balanced on it.

At temperatures between 1,300 and 1,600°C, a metal that serves as a solvent melts. This produces high-purity carbon, which is deposited around the diamond seed.

This method produces colourless diamonds. Coloured diamonds in pink, blue or yellow are also grown using additives in the HPHT process.

Special features of the HPHT process

Imitates the main conditions of natural diamond growth
Pressure of 5-6 GPa (around 5,500 bar) matches the pressure deep in the earth at around 150-190 km
High temperature between 1,300 - 1,600°C
Growth time in the HPHT process: 1 carat up to 5 days, depending on quality

The HPHT process

Base: diamond seed at the bottom of the high-pressure chamber
Carbon source mixes with metallic solvent/catalyst
Temperature gradient: hotter around the carbon source than around the diamond seed
As the temperature increases, the metal used as a solvent melts
Carbon atoms dissolve in the metal
Carbon atoms form the diamond crystal on a cooler nucleus
One or more crystals grow, depending on the press and capsule design

Chemical vapour deposition (CVD)

Chemical vapour deposition was developed in the 1980s.

With this technology, growers can produce diamonds at moderate pressure and temperatures of 700 to 1,300°C. To do this, they pump carbon-containing gas into a vacuum chamber. The carbon is deposited on a diamond seed and crystallises there as a diamond.

The CVD process allows for precision dosing of additives, which means that the desired characteristics can be planned down to the last detail. Ideal for diamonds that have to meet the high demands of the jewellery industry.

Special features of the CVD process

Requires low pressures and moderate temperatures
Diamond is mechanically stable, but unstable at high temperatures
Low probability of diamond formation, enormous energy required to destroy the diamonds formed
Growth time in the CVD process: 1 carat up to 10 days, depending on quality

The CVD process

Base: Diamond plate as template/nucleus
Gases flow through the reactor and are then activated (e.g. by microwaves)
Gaseous molecules react with diamond substrate
Diamond is deposited on the substrate "layer by layer"
Optional: addition of substances for colour changes to brown, pink, light yellow, blue, green, colourless/almost colourless

Advantages and disadvantages of HPHT and CVD

Both methods have their specific advantages and disadvantages. The choice between HPHT and CVD depends on the requirements for the diamond.

Advantages of the HPHT process

Efficiency: HPHT is a proven method that has been reliably producing large quantities of synthetic diamonds since the 1950s.
Costs: production costs are relatively low as the technology is well established.
Quality: HPHT diamonds have fewer inclusions than many of their natural counterparts because they grow in a very clean environment.

Disadvantages of the HPHT process

Energy consumption: the process requires extremely high temperatures and pressures, which leads to high energy consumption.
Limited size: it is difficult to produce very large diamonds using this method.
Metallic inclusions: HPHT diamonds almost always contain metallic inclusions that originate from the catalysts used.

Advantages of cultivation using CVD

Purity: as the process hardly introduces any foreign substances into the diamond, CVD diamonds are purer at a comparable cost.
Control: the process enables precision control of growth, resulting in uniformly grown, high-quality diamonds.
Flexibility: in the CVD process, diamonds grow on various substrates and in variable shapes.

Disadvantages of CVD

Costs: the investment for CVD systems is high, and the process is also comparatively expensive.
Speed: growth with CVD takes longer than with HPHT, which increases production time.
Technical complexity: the process requires precision control and monitoring, posing a technical challenge for the employees.

Historical development of laboratory methods

1953: first synthetic diamond produced using the high-pressure, high-temperature (HPHT) process. The diamonds are used in electronics and laser optics as well as abrasives and for other industrial purposes.

1970s: American researchers at General Electric produce the first laboratory-grown diamonds of gemstone quality. They are just clear enough and, at around 0.3 carats, large enough to be suitable for jewellery. Their colour - between J and F - was clearly visible. GIA scientists publish the first scientific study on laboratory diamonds in 1971.

1980s: manufacturers begin to produce large quantities of laboratory-grown diamond crystals. These laboratory diamonds are initially small and yellowish or brownish in colour. Processes are further optimised, which also improves quality over the course of the 1980s.

2000s: the CVD process is established for the production of gem-quality diamonds. It is considered more challenging but also more flexible than the HPHT method.

2010s: colourless, lab-grown diamonds are available in large quantities on the jewellery market. New record sizes are reported almost daily. Sales in the jewellery industry rose to around eight percent of the global diamond market.

2014: the company New Diamond Technology (NDT) starts producing large colourless laboratory diamonds of up to 5.11 ct using the HPHT process.

2015: NDT produces the first colourless, laboratory-grown HPHT diamond weighing more than 10 carats.

2016: the GIA reports a faceted 5.19 ct CVD diamond that is almost colourless. In the same year, the Institute documented the largest HPHT diamond to date with 15.32 carats of comparable quality.

2017: China claims to grow HPHT diamonds with a total gemstone weight of 200,000 carats every month.

2018: At a gemstone fair, an exhibitor presented a CVD diamond weighing 6.21 ct. NDT tops this many times over with an extremely large HPHT diamond weighing a total of 103.5 carats.

In the same year, the De Beers brand "Lightbox" is launched. Under this label, De Beers sells jewellery with white, blue and pink laboratory diamonds for 800 dollars per carat.

2020: a new record for CVD-grown diamonds: 10.75 ct. Meylor Global produces black diamonds weighing 115.65 and 109.58 ct using the HPHT process.

2023: Ethereal Green Diamond, based in India, has the largest polished diamond in history certified by the IGI. The 50.25 carat emerald-cut gemstone has the colour G and clarity VS2.

It is considered to be the world's first cut, laboratory-grown diamond over 50 carats. The rough diamond cultivated using the CVD method grew over a period of eight months.

2024: IGI certifies a cut 75.33 carat CVD diamond that bears the name "Celebration of India". It also comes from Ethereal Green Diamond. It took 270 days to grow the 190 carat rough diamond and a further 30 days to cut and polish it.

Laboratory and natural diamonds: the advantages and disadvantages

Environmental friendliness and sustainability

The founder of ADA Diamonds, Jason Payne, does the maths: the most efficient method he knows of for producing artificial diamonds requires around 250 kWh of electricity per carat. This is roughly equivalent to the amount of electricity consumed by the average German household in a month.

Some experts estimate consumption to be significantly higher and speak of 500 to 750 kWh per carat. Others publish lower consumption figures. Critics assume that these analyses include all diamonds produced, including rejects.

On the other hand, the extraction of natural diamonds requires significant interference with nature.

For every carat of natural diamonds, miners extract around one tonne of rock and need energy for extraction, transport and refinement. The diamond miners are currently keeping quiet about how much this is per carat.

Complex interrelationships make comparison difficult

It is questionable whether the figures can be compared at all. How do you eliminate the poorer diamond qualities when mining natural diamonds? How do you record the environmental aspects of the electricity mix used for the cultivated diamonds? After all, the largest producers of laboratory diamonds are located in China, which generates two thirds of its electricity from coal. Other major players come from India, where 75% of energy comes from coal.

The picture is similarly ambiguous when it comes to the social aspects. Around 10 million people currently work in the traditional diamond industry worldwide. They generate eight billion dollars a year in Africa alone. And African producer countries are among the wealthiest countries in Africa today.

Wealth from the diamond trade in Botswana

Take Botswana, for example: there, diamond exports have played a major role in making the country's economic success a role model for the entire continent. Botswana became independent in 1966 and was one of the poorest countries in the world at the time. Today, it is considered one of Africa's model countries and generates 50 per cent of its national budget from the export of diamonds.

Companies only need a few people to produce laboratory diamonds. Large corporations dominate significant portions of global production, and small companies are rare.

"Is it ethically responsible to discourage people from buying diamonds from emerging markets? Millions of people there are dependent on the labour," says Brooks-Rubin, political advisor at the NGO Enough Project.

In the end, everyone has to decide for themselves; both types of diamonds have advantages and disadvantages. And there is no clear answer to the social question and the aspect of sustainability.

Price trends and savings on artificial diamonds

Artificially produced diamonds are significantly cheaper than natural diamonds. They cost up to 80% less with comparable quality and physical properties.

An engagement ring with a 0.75 carat laboratory diamond is available for around 1,000 euros. This corresponds to around 20 per cent of the price of a ring with a real stone.

The price of a one-carat laboratory diamond has fallen by between USD 4,500 and USD 5,000 since 2016. It is currently unclear whether and, if so, to what extent the prices for lab-grown diamonds will fall. The only thing that is certain is that the technology for growing diamonds is becoming cheaper and cheaper. We therefore assume that competition will increase and that laboratory diamond prices will continue to fall as a result.

Quality and purity

Stones grown under laboratory conditions in a short time are significantly purer than those formed naturally. Due to the extremely long growth phase in an uncontrolled environment, impurities are more likely in real diamonds.

Laboratory-grown stones may have inclusions. In the HPHT process, the laboratories used catalysers which, under certain conditions, lead to metallic inclusions in the stones produced. Diamonds grown using the CVD method have a higher purity. Specific substances are added to the diamond to give it certain properties, for example to ensure that it conducts electricity.

Before buying, we recommend ensuring that the desired laboratory diamond has a gemstone certificate documenting its purity. This is especially true for larger sizes from 1 carat, as inclusions are more visible there.

Buying advice for engagement rings with lab diamonds

Laboratory diamonds are an excellent alternative to natural diamonds. They offer the same properties, are chemically identical, but significantly cheaper. For all buyers of an engagement ring with laboratory diamonds, there are a few important aspects to consider.

When buying a laboratory diamond, the 4 Cs play a role: carat, cut, colour and clarity. These factors also determine the quality and value of artificial diamonds.

The cut should be at least very good. Its quality depends on the skills of the stone cutter and has a fundamental influence on the brilliance of the diamond. The same applies to purity. When it comes to colour, it all depends on personal taste.

Certifications and quality labels

Demand a certificate of quality that exactly describes and assesses all the quality factors mentioned. Make sure that the laboratory diamond is certified by a recognised organisation such as the GIA or the IGI.

The IGI specialises in the certification of laboratory diamonds. The certificates guarantee the quality of the laboratory-produced diamond and confirm the stone's properties.

Price comparison and budget tips

Laboratory diamonds are around three quarters cheaper than natural diamonds. Nevertheless, it is worth comparing prices to find the best deal. The ring band and the selected precious metal are much more important for a ring with an artificial diamond. If you choose a less expensive metal, you can save even more here.

We believe that it makes sense to find out about current market prices for laboratory diamonds. However, seasonal discounts generally play hardly any role in jewellery.

Conclusion and forecast

Summarised here are all the important aspects as well as the advantages and disadvantages of buying engagement rings with lab diamonds.

An apt comparison: lab-grown diamonds are like ice from the freezer, natural diamonds are like glacier ice that is thousands of years old.
Laboratory diamonds are a popular alternative to natural diamonds
They are up to 80 per cent cheaper than natural diamonds, although natural diamonds have been more stable in price in the past
There are no restrictions for the jewellery design
A huge selection of colours is available
Sustainability, energy consumption, the environment and ethical aspects play a role for many buyers, but are the subject of heated debate.
Couples who own rings with lab diamonds would buy them again
These are real diamonds, produced in the laboratory
Laboratory diamonds are chemically and physically identical to natural diamonds
Even a trained gemologist can only detect differences to natural diamonds by using specialist instruments
Production using two methods: High Pressure High Temperature (HPHT) and Chemical Vapour Deposition (CVD)
Production of laboratory diamonds since the 1950s and improvement of methods to date
Higher purity and quality easier to achieve under laboratory conditions
The precious metal used plays a greater role in the price than for rings with natural diamonds
Recommendation: only buy diamonds with a certificate from a recognised institute

Prospects: market adaptation, acceptance and growing importance

The continuous improvement of techniques for the production of laboratory diamonds is leading to fewer and fewer rejects. The price is also likely to fall in the medium term.

It is possible that new and previously unknown types of diamonds will be created in the future as a result of technological progress. This would contribute to laboratory diamonds gaining further importance in the jewellery industry.

More and more jewellery manufacturers and retailers are integrating laboratory diamonds into their collections. This shows a growing acceptance and reflects the wishes of consumers.

With a view to sustainability and ethical consumption, it is possible that lab-grown diamonds will play an even greater role. An important prerequisite for this is that the energy consumption for production is significantly reduced.

Laboratory diamonds are already complementing the market for natural diamonds and may even be helping to change it for the better.