Where to Buy Lab Grown Diamonds in London

A practical guide for anyone shopping for a lab grown diamond in the capital. Last reviewed September 2026.

London is one of the best places in the world to buy a lab grown diamond, but it is also one of the easiest to get wrong. Prices for the same stone can vary widely from one door to the next, and the labels on a window tell you very little about who actually made what is inside. This guide walks through what to check before you buy, how the Hatton Garden trade really works, and the practical business of seeing stones in person.

We are a lab grown diamond jeweller based in Hatton Garden, so we have a point of view. We have tried to keep this useful rather than promotional. Where Luma is genuinely different we say so and explain why. Everything else is here to help you buy well, wherever you end up buying.

First, what a lab grown diamond actually is

A lab grown diamond is a real diamond. It has the same chemical composition, crystal structure and optical properties as a mined stone, and the same hardness. The only difference is origin. One grew over billions of years underground. The other grew in a matter of weeks in a controlled environment, using one of two methods, either High Pressure High Temperature or Chemical Vapour Deposition.

Because a lab grown diamond is not scarce in the way a mined one is, it costs a fraction of the price for the same size and quality. That is the whole reason the category has grown so quickly. You can put your budget into a larger stone, a better cut, or a finer setting, rather than into rarity.

Why London, and why Hatton Garden

Hatton Garden has been the centre of the London diamond trade since the nineteenth century. Within a few streets around EC1 you have the highest concentration of diamond dealers, goldsmiths and setting workshops in the country. That density is the reason to buy here. It means the person selling you a ring is often working a few doors from the bench where it is made, and it means you can compare real stones in person on the same afternoon.

The West End, and Mayfair in particular, is the other London option. Showrooms there tend to be larger and more polished, and the experience is more of a boutique one. You pay for that setting in one way or another. Neither area is right or wrong. Hatton Garden rewards people who want to be close to the making. Mayfair suits people who want a showroom experience and are less concerned with where the work happens.

What to check before you buy

Most of the risk in buying a diamond comes down to a few questions that are easy to ask and revealing to answer.

Independent certification

Every lab grown diamond worth buying comes with a grading report from an independent laboratory such as IGI. The report confirms the carat weight, cut, colour and clarity, and it should be laser inscribed on the girdle of the stone so you can match the diamond to its paperwork. If a seller cannot show you a report, walk away. At Luma every diamond we set is independently certified, and we check each stone by hand in Hatton Garden before it is set.

Where the ring is actually made

This is the question the trade would rather you did not ask. Plenty of brands design in the UK and then send the making overseas or out to distant factories. There is nothing dishonest about that, but it changes who stands behind the work and how close the maker is to the trade. What matters is whether the work stays local. Most of our pieces are made by skilled benches here in Hatton Garden, finished and set in London, and we check every diamond by hand before it is set. Ask any jeweller where the work is done. The answer tells you a lot.

Hallmarking

Any gold or platinum item sold in the UK above the legal weight threshold must carry a UK assay office hallmark. It is a legal guarantee of the metal purity. Our pieces are UK hallmarked, and you should expect the same from anyone you buy from here.

Transparent pricing

Ask for the price broken down. A clear jeweller can tell you what the stone costs, what the setting costs and what the making costs. When pricing is vague or moves around depending on how interested you seem, that is a signal. We price directly, without the markup that comes from selling through a retail chain, and we are happy to show how a price is built.

Where to see stones in person

You can buy a lab grown diamond online in London and many people do. Certification means you can shop on paperwork with real confidence. But a diamond is one of the few purchases where seeing it in person still matters, because cut and character do not fully come across on a screen.

If you want to see stones in Hatton Garden, most workshops here, including ours, work by appointment rather than as walk in shops. Booking ahead is not a formality. It means the person you meet has time set aside for you, the stones you want to compare are ready, and you are not waiting behind a queue. Come with a rough sense of your budget, the shape you are drawn to, and whether you are buying a loose stone, a finished piece or a fully bespoke design. That is enough to have a genuinely useful first conversation.

How buying at Luma works

We are a direct to consumer lab grown diamond jeweller in Hatton Garden, founded in 2024 by Asher Wiener and Amir Sharabi. We design engagement rings, earrings and everyday diamond pieces, made by benches here in Hatton Garden, and we take on bespoke commissions from a sketch or an idea.

Every diamond we set is lab grown and independently certified. Every piece is made to order by Hatton Garden benches, finished and set in London, UK hallmarked, and carries a one year manufacturing warranty. Most pieces are made to order and ready in 4 to 6 weeks. Ready to ship pieces are dispatched within one to two business days. Every Luma ring includes one free resize within the first 12 months. You can buy online for UK and international delivery, or book a private appointment to see stones and settings in person before you decide.

Book a private appointment in Hatton Garden

Common questions

Where can I buy lab grown diamonds in London?

The main options are Hatton Garden in EC1, which has the highest concentration of diamond specialists and setting workshops in the UK, and the West End around Mayfair, which leans toward larger boutique showrooms. Many jewellers also sell online for delivery. Hatton Garden is the place to be close to where rings are actually made, and most workshops there see clients by appointment.

Are lab grown diamonds real diamonds?

Yes. A lab grown diamond has the same chemical composition, crystal structure, hardness and optical properties as a mined diamond. The only difference is that it grew in a controlled environment rather than underground, which is why it costs far less for the same size and quality.

Is Hatton Garden a good place to buy a lab grown diamond?

It is one of the best in the world for it. The density of dealers, goldsmiths and workshops in a few streets means you can compare real stones in person and buy close to the bench where the ring is made. The one question worth asking any Hatton Garden jeweller is whether they make locally or send the work out, because many outsource the making.

How much do lab grown diamonds cost in London?

Far less than a mined diamond of the same specification, often a fraction of the price. The exact figure depends on carat weight, cut, colour, clarity and the setting you choose. A clear jeweller will break the price down into the stone, the setting and the making, so you can see what you are paying for.

What certification should a lab grown diamond have?

Look for an independent grading report, from a laboratory such as IGI, with the details laser inscribed on the girdle of the stone so the diamond can be matched to its paperwork. If a seller cannot produce a report, do not buy the stone.

Do I need to book an appointment to see lab grown diamonds in London?

In Hatton Garden, usually yes. Most workshops, including ours, work by appointment rather than as walk in shops. Booking ahead means the stones you want to compare are ready and someone has time set aside for you. It is worth arriving with a rough budget and a sense of the shape you prefer.

How long does a Luma piece take to make?

Most pieces are made to order in Hatton Garden and take 4 to 6 weeks before dispatch. Ready to ship pieces leave within one to two business days.