The Science Behind Lab Grown Diamonds: How Are They Made?

Lab-grown Diamonds (LGD) are sustainable and ethical alternatives mirroring optical, physical and chemical properties to their natural diamonds. Also called synthetic diamonds, LGDs are made of pure carbon atoms, arranged in the same crystal structure as earth-grown diamonds, within a strictly and scientifically conditioned laboratory setting. This artificial setting gives the diamonds the ideal structural hardness and durability as well as the desirable dazzling appearance similar to natural diamonds.

CVD and HPHT: Lab Science Producing Diamonds.

Primarily, lab diamonds are created following these two methods: Chemical Vapour Deposition (CVD) and High Pressure High Temperature (HPHT). While CVD uses plasma deposition, HPHT uses high-pressure, high-temperature conditions for diamond growth. Both of the CVD and HPHT processes simulate the physical and atmospheric conditions under which natural diamonds form deep below the Earth's mantle. Thus, both effectively end up producing high-quality diamonds, identical to their natural counterparts.

We will discuss both these methods in detail further down. But before that, let’s explore other areas as well - areas that usually zip through the mind when you hear about lab-grown diamonds.

Where are lab diamonds made?

As the name suggests, lab-grown diamonds are produced within scientific laboratories equipped with cutting-edge technology to artificially control the conditions required for producing diamonds. Countries, like - USA, China, Singapore and Israel have already established a thriving market of lab-grown diamonds. Recently India has also contributed in the escalating online market centred around the production and worldwide transportation of lab-grown diamonds, thus affecting a number of industries, including the jewellery industry of the country. To know more about the lab-grown diamond market in India, check out this recent The Hindu article.

We, Stella Fine Jewellery, are glad to inform you that we are one of those promising Indian companies who leverage their expertise in producing and marketing to deliver their finest lab-grown diamond products to their customers.

What is a lab-grown diamond made of?

Like its natural alternative, a lab-grown diamond is a result of effectively arranged carbon atoms structured to provide it the desired hardness, durability and radiance for use in jewellery. However, lab-grown diamonds differ from the earth-grown diamonds in the aspect of the processes behind their making. While the traditional process consumes a lot of time and energy, as well as costs a vast expanse of land to produce, explore and dig-out the earth-grown diamonds, modern technology demands a more sustainable alternative to produce LGDs.

Chemical Vapour Deposition (CVD) and High Pressure High Temperature (HPHT) are two such processes that receive increasing attention to produce lab-grown diamonds. Here in Stella Fine Jewellery, we exercise the CVD method in monitoring and adjusting factors such as temperature, pressure, and gas composition in our scientific labs equipped with advanced technologies to deliver the desired diamond products directly to you.

Chemical Vapour Deposition (CVD) Diamonds

What is CVD? Chemical Vapour Deposition or CVD is a man-made scientific process which simulates the natural process of the formation of diamonds in interstellar gas-clouds. Comparatively a newer process, CVD was first introduced during the 1980s. Moreover, CVD is a more affordable approach as compared to HPHT as it requires less production costs.

Steps: The steps to create CVD diamonds in a lab are as following -

1. Starting with a Seed: The process begins with selecting a small seed diamond of around 10 x 10 mm proportions and 300 microns thickness. The base for the new diamond to grow, this seed diamond can either be natural or lab-grown.
2. Creating a Diamond-Friendly Environment: Inside an enclosed chamber, carbon-rich gases, like methane, are introduced and heated to around 1000 Fahrenheit. These gases will provide the carbon needed for the new diamond to form.
3. Turning Gases into Plasma: Microwaves, lasers or other devices are then used to ionise the gases to turn them into plasma, which is a supercharged state of matter.
4. Building the Diamond Layer by Layer: The carbon ions in the plasma start to stick to the seed diamond's surface, building up layers of carbon atoms. This process mimics how diamonds form from interstellar gas clouds naturally for over thousands of years.
5. Growing the Diamond Crystal: Over time, the carbon atoms keep stacking up on the seed inside the carefully monitored lab, gradually forming a diamond crystal.

Once the CVD diamond has grown to its desired size, it goes through the process of cutting, polishing, and cleaning to make it ready to be used in jewellery.

Additional Information: CVD process always makes a better choice for producing lab-grown diamonds as it is quicker, less costly and uses less energy. But there is a general assumption that because of all these reasons, CVD produces diamonds that are lower-quality than HPHT diamonds. However, it is to remember that it is the CVD process that produces Type IIA diamonds - the most chemically pure diamonds as they lack boron or nitrogen impurities unlike HPHT diamonds

How to identify CVD Diamonds: CVD diamonds, when they are freshly removed from the chamber, acquire the shape of a cube which has one-point direction. They are often reported to have “strain lines” as a result of the gradual growing process or to reflect fluorescent colours like red when held under UV light. However at Stella Fine Jewellery, we guarantee you the finest CVD diamonds with as admirable qualities as natural diamonds and with almost zero or none of such afore-mentioned deficiencies.

High Pressure High Temperature (HPHT) Diamonds

What is HPHT? High Pressure High Temperature or HPHT is an artificial scientific process which resembles how diamonds are created under the natural environment of high temperature and high pressure underground the earth - inside its interior. Industrially, this process was initiated in the 1950s. Other than producing lab-grown diamonds, HPHT process is also exercised to improve the clarity and colour of mined diamonds.

1. Starting with a Seed: Like CVD, creating lab-grown diamonds in this process also begins with selecting a small diamond seed, which is a tiny piece of natural or lab-grown diamond.
2. Creating a Diamond-Friendly Conditions: The seed is placed in a growth-chamber along with carbon-rich material, like graphite, and metal catalysts.
3. Applying Pressure: The chamber subjects the seed to extreme pressure, mimicking the conditions deep within the Earth where natural diamonds form. This pressure can amount up to 1.5 million PSI. There are 3 techniques to apply pressure on the seed - the split sphere (BARS) press, the cubic press and the belt press. To know more about the press-techniques in HPHT, you can visit the website of IGS.
4. Applying Heat: It is then subjected to high temperature reaching to around 1,500 degrees Celsius (2,700 degrees Fahrenheit). This heat helps the carbon atoms in the graphite to move and attach to the diamond seed.
5. Diamond Formation: Under these intense conditions, the carbon atoms from the graphite start to attach themselves to the diamond seed, gradually building up layers of diamond around it.
6. Cooling Down: After the diamond has grown to the desired size, the chamber is slowly cooled down over several hours to allow the newly formed diamond to solidify and stabilise

Once the HPHT diamond has grown to its desired size and is stabilised, it goes through the process of cutting, polishing, and cleaning to make it ready to be used in jewellery.

Additional Information: HPHT diamonds usually have a yellowish tone due to their exposure to nitrogen while forming. They also have dark, metallic inclusions that make them magnetic unlike natural diamonds. HPHT diamonds, unlike CVD diamonds, rarely require post-growth treatments.

How to Identify HPHT Diamonds: Other than referring to the grading report, you can identify a HPHT diamond on the basis of the afore-mentioned qualities. Once they are freshly collected from the chamber, they acquire the shape of a cuboctahedron with the growth in 14 directions. Furthermore, some HPHT diamonds stand out for their unique bluish emission which is known as blue-nuisance.

Certification and Grading

LGDs are certified by independent gemological laboratories, such as the Gemological Institute of America (GIA), using the same grading standards as natural diamonds. While in India, lab-grown diamonds are certified primarily by two prominent gemological institutes: the Solitaire Gemmological Laboratories (SGL) and the International Gemological Institute (IGI).

Both these certifications for LGDs are based on the 4Cs (Cut, Clarity, Color, and Carat weight) and other quality factors. These certification processes involve a detailed examination of lab-grown diamonds by trained gemologists using specialised equipment to confirm their authenticity and quality.These certificates provide a comprehensive information about the lab-grown diamond, including its 4Cs, dimensions, and any additional features that may affect its value or appearance.

Both IGI and SGL certificates thus form the inseparable parts to the lab-grown diamonds to prove their uniqueness in this escalating online jewellery industry, providing consumers with confidence in the quality and authenticity of the lab-grown diamonds they are purchasing. Accordingly, here in Stella Fine Jewellery, we assure you to provide the finest, SGL-certified lab-grown diamonds. To know more about the SGL certification process, visit the official website

How long does it take to make a lab-grown diamond?

The time it takes to produce a lab-grown diamond varies depending on the size and quality desired. It typically takes several weeks to several months to grow a lab-grown diamond. Additionally, larger and higher-quality diamonds may take longer to grow than smaller or lower-quality ones. Overall, growing a lab-grown diamond is a precise and time-consuming process that requires patience to achieve the desired result.

At Stella Fine Jewellery, we craft jewelleries out of such CVD diamonds that not only bear marks of patience, but also care - diamonds that not only require considerable time to be created, but also diamonds that stand out for their uniqueness and magnificence.

Do lab diamonds test as real diamonds?

Yes, lab-grown diamonds have the same physical as well as optical properties as natural diamonds and are indistinguishable from them. In scientific terms, they also test as chemically similar to natural diamonds in gemological tests conducted by labs such as SGL and IGI.

Do lab diamonds come in different colours?

Yes, lab-grown diamonds can be artificially manipulated to radiate a variety of colours, including white, yellow, blue, pink, and green. In the HPHT process, these colours are achieved by introducing trace elements, such as nitrogen or boron during the diamond growth process. For example, introducing boron into the process will give the diamond blue colour, whereas introducing nitrogen will give the diamond a yellow colour.

Do lab-grown diamonds last as long as natural diamonds?

Yes, they are just as durable as natural diamonds and can last for generations with proper care. They are resistant to scratching and chipping, making them suitable for everyday wear.