SUSTAINABLE BLUE LAB DIAMOND GUIDE
Buying advice, quality & facts
Colour
Blue
Our Source
Global
Mineral class
Carbon
Hardness
10 Mohs Scale
Birthstone month
April
Wedding anniversaries
10th and 60th
Sustainable blue lab grown diamonds are real diamonds, just like mined blue diamonds. Physically and chemically the same as their earth-mined counterparts, they’re also equally vividly coloured, beautiful and sparkling. The only difference is their origin.
Scientists grow blue lab diamonds in a laboratory using a method that imitates the way Mother Nature formed blue diamonds under the earth.
Blue lab grown diamonds offer superb natural colour, beautiful sparkle and exceptional value. What’s more, they’re a sustainable choice.
Growing real blue diamonds in a laboratory is fascinating. Every single lab diamond starts as a tiny fragment of a mined diamond, which is exposed to carbon. Carbon is the element that all diamonds are created from, whether earth-mined or lab-grown.
Earth-mined blue diamonds owe their colour to boron trace elements. When it comes to lab grown blue diamonds, the same natural colouration is achieved through a process that imitates nature.
In the laboratory, scientists introduce boron trace elements while the diamond grows. This results in beautiful, naturally blue colour within the diamond crystal.
Over a few weeks, the carbon atoms crystalise and grow into rough blue diamonds. Once they’re large enough, they can be carved into beautiful gems and worn in jewellery.
Blue lab grown diamonds are environmentally ethical and sustainable. Their carbon footprint is much smaller than that of mined diamonds, because they are not extracted from the earth.
While our mined diamonds are also ethical because they are conflict-free, our lab grown diamonds give you a further choice: jewellery that nurtures the Earth for future generations.
Blue lab grown diamonds are real diamonds, created in a way that replicates nature. Therefore, gemmological experts grade them exactly in the same way as mined blue diamonds. This is done by evaluating the “Four Cs” – cut, colour, clarity and carat weight, with special importance placed on pure and even colour.
When it comes to white diamonds, they usually decrease in value if any colouration is seen in their transparent crystals.
For coloured diamonds, the opposite is true. The better their colour, the higher their value.
However, grading coloured diamonds is a complicated and specialized process. What’s more, just like earth-mined blue diamonds, lab grown blue diamonds can vary in shade from light to intense. This is completely natural, same as it would be in earth-mined blue diamonds. No two diamonds are exactly alike.
Therefore, you should look for evenness and purity of colour, rather than an individual tone or shade which can vary from diamond to diamond.

All diamonds have some imperfections. Gemmologists call these tiny markings “inclusions”. Generally speaking, the less inclusions your diamond has, the better its clarity. Remember, that blue lab diamonds are grown in a way that imitates Mother Nature. Therefore, they are not free from natural imperfections.
When it comes to earth-mined blue diamonds, inclusions are tolerated by gem connoisseurs. This is because mined blue diamonds are very rare. Even a poor-clarity mined blue diamond can fetch prices starting from around from £2,000 per carat.
Luckily, blue lab grown diamonds are created in a laboratory. This means that it is reasonably cost-effective to select the clearest blue diamonds from each batch that is grown.
What does this mean for the consumer? It means that you can expect to find a far better clarity of blue lab diamond for your budget, than if you were shopping for an equivalent-sized blue mined diamond.
FL (flawless) diamonds have the best clarity. Diamonds graded I (visible inclusions) are the poorest. Most people seek diamonds in between the two extremes: VVS (very, very slight inclusions), VS (very slight inclusions) or the most popular grade, SI (some inclusions).

When we speak about a diamond’s “cut”, many people think about its decorative shape. For example, you might imagine a classic round cut diamond or a square princess cut diamond.
However, in reality, when we talk about “cut quality”, it refers to how well the diamond plays with light.
A good diamond cut should make your diamond sparkle beautifully. This depends on the skill and expertise of the diamond cutter who carved and polished the diamond out of a rough gem.
We offer a minimum of Good/Very Good cut in all our over-0.50 carat lab and mined diamonds that have H/Si quality or higher.

“Carat” refers to a diamond’s weight. In other words, it tells us how big the diamond is. You’ll often see carat weight abbreviated to “CT”. For example, 1.00CT means one carat and 0.50CT means half a carat.
A blue lab diamond’s price is not necessarily determined by its carat size. Remember, all Four C’s, and in particular purity and evenness of colour, must be taken into account.
However, the good news is that coloured lab diamonds award you up to 75% more carats for your budget, compared to mined ones.
Therefore, you will definitely be able to purchase a much, much larger blue lab grown diamond for your budget, than if you were buying a mined blue diamond of the equivalent quality.

We also offer sustainable white lab grown diamonds and pink and yellow lab diamonds in our online store. You’ll find a Gem Guide for each one, under White Lab Diamonds, Pink Lab Diamonds and Yellow Lab Diamonds.
Yes, blue lab diamonds are real diamonds. Gemmological experts classify coloured lab grown diamonds simply as, coloured diamonds. This is because they posses the same physical and chemical composition as the diamonds we mine from the earth.
It’s vital to understand that blue lab diamonds are NOT synthetic diamond “substitutes”. They are not like cubic zirconia, moissanite or other simulants, which are manufactured from materials that have nothing to do with diamonds.
Because blue lab grown diamonds look the same as blue mined diamonds, for consumer transparency they all carry a microscopic laser mark. This way, jewellers can tell them apart with specialist magnifying equipment.
Yes. Same as mined diamonds, blue lab diamonds can be certified to prove their Four Cs and origin.
However, note that not all blue lab or mined diamonds are certified. Why? Diamond certification is an expensive process. Adding this cost to, for example, a small diamond under 0.25 carat would make it unnecessarily and disproportinately expensive.
Who certifies lab grown diamonds? They are certified by exactly the same independent gemmological laboratories that certify mined diamonds. For example, GIA or IGI laboratories.
Diamonds are the birthstone for April. This applies to all diamonds, be they earth-mined, lab grown, pink, yellow or blue.
Because of their durable nature, they represent lasting love and affection. That’s why they’re so often used in symbolic jewellery, especially in engagement rings.
Diamonds are traditionally gifted on 10th anniversaries and 60th Diamond Jubilee Wedding Anniversaries, but their beauty and value mean they’re well suited to any important occasion.
All diamonds should be cleaned with care and stored in a safe place. Whilst they are the most durable and strong material on Earth, they’re precious and rare gems.
The safest way to clean your blue diamond jewellery is in a bowl of water using a drop of soap and an old toothbrush. Give the jewellery a gentle scrub, then rinse and pat dry.
Never wash your diamond jewellery over a sink. Use a bowl instead. Should a diamond come loose, this way it cannot disappear down the drain.
The very definition of diamonds is changing thanks to state of the art technology and the value we put on sustainability. This is especially true for modern celebrities and fashion lovers.
Lady Gaga, Penelope Cruz, Meghan Markle, Emma Watson and Zoe Kravitz are just a few of the big stars who habitually flaunt sustainable lab grown diamonds on red carpets.
Blue lab grown diamonds are a luxury. As such, they are rare and by no means inexpensive. The perception of their value is simply different because lab diamonds grow withing a few weeks, as opposed to mined diamonds which take billions of years to form.
Just the same as blue mined diamonds, the price of blue lab diamonds varies according to the Four Cs – colour, clarity, cut and carat weight.
The good news for consumers is that if you compare a blue mined and a blue lab diamond of the same quality and size, you’ll get up to 75% more carats for your budget if you buy the lab grown varity.
Finally, adding unmeasurable value to blue lab diamonds is their sustainability. If you are concerned about the carbon footprint of diamond mining, then blue lab diamonds, which nurture our Earth for future generations, are the perfect choice for you.
We want you to feel completely confident when you shop with us. That’s why we offer FREE 30-day returns for refunds and 60-day exchanges across the UK and Northern Ireland.
If you’ve ordered a ring smaller than a size J or larger than a size Q, don’t worry — these are custom sizes, but we’re still happy to offer a free exchange or resizing if the fit isn’t quite right.
Changed your mind? No problem — you can cancel your order anytime before it’s been dispatched.
Just reach out to our friendly team via Live Chat, by email at customerservice@thediamondstore.com, or give us a call on 0345 084 1200 (or +44 345 084 1200 if calling from outside the UK). Please have your order number handy to help us assist you as quickly as possible.
Please note that for rings smaller than size J or larger than size Q, the width may vary slightly (up to 10%) due to the crafting process. If you need any adjustments, we’re happy to help.
If your item arrives damaged or defective, we’ll make it right — fast. We’ll either repair or replace it at no cost to you, or provide a refund once it’s been assessed by our head jeweller.
Our standard returns policy is 30 days to return, and 60 days to exchange.
We stand by the quality of our jewellery. That’s why all our pieces come with a 5-year warranty against defects in materials or craftsmanship. Every item is also fully hallmarked according to UK legislation, confirming its authenticity and origin.
Once we’ve received and inspected your returned jewellery, we’ll process your refund right away and email you to confirm. Depending on your bank or payment provider, it may take 3 to 5 working days to show up on your statement.
We’ll always refund you via the same method you used to make your purchase — whether that was credit or debit card, PayPal, Pay4Later Finance, bank transfer, or another option.
To avoid delays, make sure to include the returns label print-out with your parcel. This helps us identify your return quickly.
We’re proud to say that all our diamonds are conflict-free and fully compliant with United Nations regulations. When you buy from us, you’re choosing ethical beauty.
We’re here whenever you need us.
📧 Email us: customerservice@thediamondstore.com or returns@thediamondstore.co.uk
📞 Call us: 0345 084 1200 (UK) or +44 345 084 1200 (International)
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