Lewis Malka

Diamond Bourse, 100 Hatton Garden, EC1N 8NX · View on Google Maps · Visit website · 02074044022

Lewis Malka began his apprenticeship at sixteen, studied at the Sir John Cass School of Art, and has been in the trade for more than thirty years. He established the business in 2000 and works from inside the London Diamond Bourse at 100 Hatton Garden, where he sits on the board. That address matters: the Bourse is a trade building, not a parade of shops, so there is no window to look in and nothing to walk past.

What you get instead is the jeweller himself. No sales team, no consultant working to a target, and no handover from the person who advised you to the person who makes it. He estimates he has worked with more than five thousand couples, and he has written a book on choosing an engagement ring, which tells you something about how he prefers to spend a consultation.

He is also the only jeweller featured on this site who works with natural diamonds exclusively, and he argues the case publicly rather than quietly. His position is that lab-grown stones suit a buyer who wants maximum size for a limited budget, but that they do not hold value in the same way. You do not have to agree with him. You should know it before you book, because it will shape what he shows you.

Everything happens by private appointment, booked through his site or by phone, and virtual consultations are offered worldwide. The consultation is a conversation about what you are trying to achieve rather than a tour of stock, and he will walk through the trade-offs between different stones, explaining what each choice costs you and gains you, until a shortlist emerges.

If he does not already hold the right diamond, he sources it. Board membership of the Bourse means access to the trade floor and a network of dealers, which is the practical advantage of buying from inside the building rather than from a shopfront. Design then runs from initial sketch through to final polish. He does not publish opening hours, and the Bourse is a trade building rather than a shop, so agree a time when you book.

The distribution is the story. Of the 899 reviews we analysed, 898 are five star and one is four star. Nothing sits below that, across more than ten years of trading. No other jeweller on this site comes close, and it is unusual enough to be worth pausing on rather than skimming past.

Reading the reviews themselves, 110 people specifically mention how much he knew, 78 describe commissioning something bespoke, and 50 talk about coming back afterwards for resizing or aftercare. That last group matters more than it looks: people returning for service years later is harder to manufacture than a burst of positive reviews.

Two things to weigh honestly against it. The pace has slowed, with 60 of those reviews from the past year against a ten-year total, so much of this reputation was built earlier rather than recently. And a record this clean is rare enough that it is sensible to read it alongside other evidence rather than on its own. He replies to essentially every review he receives, 897 of 899, which is the highest rate we found anywhere.

Review figures taken from Google and checked in July 2026. We recount them monthly.

This suits a buyer who wants one expert rather than a showroom, and who would rather have a long conversation than a tray of options. If dealing with the same person from first sketch to final polish appeals, and you want a natural stone sourced from the trade floor rather than picked from a catalogue, that is exactly what is here.

It will not suit you if you want to browse. There is no shopfront, no stock to try on unannounced, and no walking in on a Saturday. Nor will it suit you if you have settled on a lab-grown stone, since he does not work with them and will tell you why.

Do I need an appointment to see Lewis Malka?

Yes. He works by private appointment only, from inside the London Diamond Bourse at 100 Hatton Garden. It is a trade building rather than a shop, so there is no showroom to walk into.

Does Lewis Malka sell lab-grown diamonds?

No. He works with natural diamonds exclusively and has publicly set out his reasoning, arguing that lab-grown stones suit buyers wanting maximum size on a tighter budget but do not hold value in the same way. If you want a lab-grown stone, you will need a different jeweller.

What are the opening hours?

He does not publish opening hours. His site states appointment only, with booking through the site or by phone, and virtual consultations available worldwide. Agree a time directly when you book rather than relying on third-party listings.

How good are the reviews really?

Of the 899 reviews we analysed, 898 are five star and one is four star, with nothing below that in over ten years. He replies to 897 of them. The main caveat is pace: only 60 are from the past year.