An Expert Jeweller’s Guide to Lab-Grown Diamonds
In recent years, we've been increasingly asked about laboratory-grown diamonds: Are they ethical? How do they differ from natural diamonds? Which option is better for investment? Laboratory-grown, laboratory-created, synthetic, artificial, fake and simulant: there are many confusing labels in jewellery marketing and on discussion forums. Are they the same thing?
Many jewellers shy away from addressing this topic due to its complexity and the often heated debates it sparks, preferring not to take sides. However, we believe our customers deserve access to all the information needed to make informed decisions. Transparency and honesty are at the heart of our values, and we are committed to upholding them.
What are diamonds manufactured in a laboratory called?
Laboratory-grown or laboratory-created are the correct labels, and any diamond that has been manufactured in a laboratory must be clearly identified and labelled as such. It must not be misleading nor mistaken for a natural diamond. Usually, jewellers and workshops handling both natural and laboratory-created stones will keep the laboratory-grown diamonds in a separate room or part of the building to make sure there is no confusion and stones do not get mixed up by accident. Like many certified natural diamonds, laboratory-grown diamonds also have a serial number laser inscribed on their girdles and will start with LGXXX for lab-grown. This is usually only visible through a microscope.
Other names for lab-grown diamonds
Synthetic diamonds: These are the same as laboratory-grown diamonds. They have the same properties as natural diamonds, and they are manufactured in a laboratory. You can use this label, but people find this confusing because it is closely associated with the word simulant, which is very different. Laboratory-grown or lab-created is just plain, easy to understand and does not cause confusion.
Artificial diamonds: These are the same as laboratory-grown diamonds and, again, like synthetic diamonds, you can use this to refer to laboratory-grown diamonds, but sometimes it can be mistaken for simulant diamonds.
Fake diamonds: Fake diamonds are called diamond simulants, diamond imitations, or diamond accents. They are gemstones that are made to look like diamonds, but are chemically and structurally different. They can be both man-made or natural gemstones. This term often has a negative tone, and some passionate people who label themselves as ‘purists’, preferring natural diamonds, have used this term to refer to laboratory-grown stones in a negative way, implying the stones are inferior or even fraudulent. (We did say this topic is heated!) This, however, is not accurate nor correct because laboratory-created stones have the same chemical and structural properties as their naturally occurring counterparts. Fake diamonds can include: cubic zirconia (CZ), moissanite, rhinestones, Swarovski cut glass, crystal, quartz, spinel, zircon, white topaz and white sapphire.
Simulant diamonds: A diamond simulant or imitation is a stone that mimics the appearance of a diamond. They imitate real diamonds eg. cubic zirconia or moissanite. They do not share the same physical or chemical properties as a natural diamond.
Do laboratory-grown diamonds look the same as natural diamonds?
Laboratory-grown diamonds have the same chemical composition and structural form as natural diamonds, so yes, they look the same. They are often whiter and have a higher clarity as they are grown in a controlled environment. The only difference is in the way they form, and this will be evident in their internal growth patterns and crystal markings. They will also react differently under gem testing equipment as a result of the flux solution and the process of manufacture.
How are laboratory-grown diamonds made?
Unlike natural diamonds, which grow in the Earth’s mantle and a large volume of destruction to the environment is needed to excavate them, laboratory-grown diamonds do not need such invasive measures and can be created in laboratories above ground. If you have ever bought one of those children’s crystal growing kits, you might get an idea of how crystals form in a very basic way.
With laboratory-grown diamonds, there are 2 different ways to grow them:
1. CVD (Chemical Vapour Deposition) This method can produce a small diamond in as little as two weeks and requires a large volume of hydrogen and methane gases.
2. HPHT (High Pressure, High Temperature) This method is the more common one and can take up to three months to create a larger diamond. Graphite, nickel, cobalt, and iron, amongst other raw minerals, are required to start the process.
Both methods cost about the same to produce diamonds, but they have different methods and different rates of success.
The more common HPHT diamond formation process begins with a small diamond seed crystal that is placed into a growth chamber. The diamond seed is exposed to intense pressure around 870,000 pounds per square inch and intense heat of around 1300-1600 degrees Celsius. Within the capsule, a carbon starting material, such as graphite, dissolves in a molten flux consisting of metals such as iron (Fe), nickel (Ni) or cobalt (Co), which lowers the temperature and pressure needed for diamond growth. In this environment, consequently, a diamond begins to form around the seed.
The diamonds under the HPHT method will grow with both flat tabular cubic faces and octahedral faces from the diamond “seeds.” A natural diamond will only grow in an octahedral form (and also takes 1-3.3 billion years in the Earth’s mantle!) while a CVD lab-grown diamond will only grow in cube form with flat tabular faces. The HPHT method, then, is a blend of both. On average, they take about 4 months to grow lab depending.
Like natural diamonds, lab-grown diamonds, once grown, will follow the same pathway, going to a diamond lapidarist (gem cutter) in a cutting centre, for example, in India, to be shaped and polished into the final form. It then goes on to be sold through various channels of traders and retailers.
Are laboratory-grown diamonds rare?
Laboratory-grown diamonds are not rare at all! Anything man-made in a factory environment is not rare and can be reproduced quickly. Laboratory-grown diamonds can be grown in 4 months. Laboratory-grown diamonds are also not new. They have been used for industrial purposes for decades, but until recently, the technology wasn’t available to grow gem-grade quality diamonds for jewellery. Even now, only 5 % of the world’s diamonds are used in jewellery. The rest is for industrial and technological use! The majority of the laboratory-grown diamonds are made in Asia, predominantly China and India. They have produced a large yield in such a short time frame that they have flooded the market, resulting in a rapid decrease in prices. We are also noticing that the gap between a 1.0 ct and a 2.0 ct is closing. We are seeing significantly lower prices for the same size stones we bought for jewellery a year ago. Laboratory-grown stones do not hold their value, and we need to make customers aware of this at the time of purchase.
Why are laboratory-grown diamonds increasing in popularity?
We use both natural and laboratory-grown stones and are happy to advise our clients on both to create their perfect piece of jewellery. We are honoured to be part of designing something truly unique, and for us, customer satisfaction is at the forefront of our service. We want our customers to feel they can have their dream jewellery, and that is important. Naturally, we cannot speak for the whole industry, but in our experience, we have seen an increase in laboratory-grown diamonds, mostly for three reasons:
1. The younger generations are aiming to get on the property ladder first and want to buy a larger and higher-quality diamond as an engagement ring for a more affordable and attainable price. Interestingly, though some buy a laboratory-grown diamond with the view of upgrading it to a natural one later down the line. Others see laboratory-grown diamonds as an accessible way to have higher-end quality “fashion jewellery.”
2. Some people are becoming more concerned about the ethical side of the industry, the sustainability and environmental impact and want an alternative option for diamonds that aligns more with their own values.
3. Unfortunately, crime is another reason for some of our clients. After being broken into and having had jewellery stolen, some of our clients have decided to replace their jewellery with laboratory-grown stones instead, whilst others want replicas of their higher-end pieces or heirloom jewellery so they can take them abroad on holiday without fear of losing them.
Are diamonds a good investment?
In our opinion, diamonds are not really investment products. Loose laboratory-grown diamonds are definitely not investment products. Even natural diamonds do not increase in value over time very much, and last year actually decreased slightly. It is more likely to be the gold in the jewellery that increases in value. Like any commodity, fluctuations in the market due to economic and political factors can result in increases and decreases in value, and we cannot see into the future. But we recommend liaising with a financial advisor on this subject as our expertise lies in jewellery manufacturing and not financial investment portfolios.
It can be argued, though, that depending on an item’s provenance and who designed it, a couture piece of high jewellery might increase in value and be seen as an investment, but this is very subjective, and we recommend consulting experts on this. We believe you should purchase jewellery because you love it, love the craftsmanship and enjoy wearing it.
Are laboratory-grown diamonds ethical?
The term “ethical” is deeply personal and can vary depending on values, culture, and lived experience. While lab-grown diamonds are often marketed as an ethical alternative to mined stones, the reality is more complex.
Lab-grown diamonds still require mined materials. The HPHT method uses graphite, nickel, cobalt, and iron — all of which are mined. CVD diamonds rely on methane and hydrogen, which come from fossil fuels. So, while they avoid the large-scale environmental disruption of traditional mining, they are not free from environmental impact or mining altogether.
Energy use is another concern. Most lab-grown diamonds are produced in India and China, where coal remains a primary energy source. A small number of labs in the US use green energy, but these are exceptions rather than the rule. Additionally, producing lab-grown diamonds generates waste and consumes significant power — especially when failed diamond seeds cannot be reused.
Lab transparency and working conditions also remain unclear. We don’t always know if employees receive fair pay, safe working conditions, or benefits. This lack of insight makes it difficult to assess the full ethical footprint.
At Timothy Roe Fine Jewellery, we prioritise working with trusted gemstone dealers and suppliers who share our values. We believe both mined and lab-grown diamonds have a place in the industry — and that honest, transparent practices matter most.
If you are curious or have any questions about laboratory-created stones, let us show you some stunning pieces we have made in our on-site workshop. Feel free to look at our laboratory-grown diamond jewellery on our website shop or book an appointment to see us about having something bespoke made.
More FAQs and Helpful Information
Is a lab-grown diamond actually a real diamond?
Yes, lab-grown diamonds are real diamonds. They have the same chemical composition, physical properties, and brilliance as natural diamonds. The only difference is their origin — lab-grown diamonds are created in a controlled environment, while natural diamonds form underground over millions of years.
What is the downside of lab-grown diamonds?
The main downsides of lab-grown diamonds include a lower resale value compared to natural diamonds and a lack of transparency around environmental and ethical claims. While they are often marketed as sustainable, many are produced using fossil fuels and non-renewable materials, making their overall environmental impact more complex than it may appear.
Can a jeweller tell if a diamond is lab-grown?
Yes, a jeweller with the right equipment can tell if a diamond is lab-grown. Lab-grown diamonds have distinct growth patterns and trace elements that can be identified using specialist tools, but they are otherwise visually and chemically identical to natural diamonds.
Do lab-grown diamonds lose their sparkle?
No, lab-grown diamonds do not lose their sparkle over time. Like natural diamonds, they are highly durable and maintain their brilliance and fire with proper care. Regular cleaning and safe storage will keep your lab-grown diamond looking just as radiant as the day it was made.
Useful links for further reading
The National Association of Jewellers (NAJ) has recently (2024) released its guidance notes on environmental claims and advises jewellers on careful wording when it comes to marketing jewellery. This is important for both retailers and consumers. Read more here.
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