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Lydia McCarthy-Keen London

Where love meets Luxury


Designer of luxuriously crafted and intricately refined jewellery, Lydia’s work takes the art of gift-giving to the next level. From her renowned classic engagement rings to unique one-offs, each piece is conceived in London before being handmade by specialist artisans across the UK.

The beginning of Lydia McCarthy-Keen marked a rise in public consciousness. From clothing to food production, from diamond-sourcing to jewellery design, we must return to a small scale, high quality, high welfare way of life.

This worldview is shared by all connoisseurs, and explains how Lydia's signature designs have been commissioned by well-known figures across business and the arts.


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Get Help from an Ethical Diamond Specialist

Lydia is on hand to help you find the perfect ethical diamond, luxury engagement ring, birthday or anniversary gift ideas.

What Our Clients Say

''It's the most special and stunningly beautiful piece of jewellery I've ever worn.''

Elly, New York

''It was amazing. Lydia really listened to my needs and what I was after. I felt very listened to, and not at all pushed.''

Lisa and Ian, London

‘‘Lydia helped me so much. My understanding of diamonds was limited, but she explains everything in a way which was easy to understand. I was fortunate to have the guidance of someone knowledgeable and professional.’’

Benjamin, London

‘‘Who says that love means a diamond? But tradition has made it that way, and I wanted a piece of that fairytale.’’

Florian, London

‘‘My first proposal was in 2004. I sat down with an independent jeweller who fed me some lines about the 4C’s, with a fifth being ‘confidence in your jeweller’. I swallowed every word, and was more careful this time - I feel I’ve got a top notch engagement ring from a genuinely lovely person.’’

Richard, Shropshire

''I wish we met Lydia the first time around. My husband bought me a ring I wasn't that wild about, so we decided to upgrade later. What a difference from the first experience!''

Eugene & Serena, London

The LMK Difference

All of our diamonds reach a VS or VVS clarity grade with a D-G colour and Excellent cut grade as standard.

Our natural diamonds and gemstones are ethically sourced from trusted partners. Each partner is regularly vetted, and must meet the LMK Green Rating™ in addition to internationally recognised ethical standards.

We apply the same ethical rigour to our lab grown diamonds and expect our partners to be actively utilising and systematically increasing their use of renewable energies year-on-year.

Once a prospective LMK Diamond™ has passed ethical assessments, we select only those which display the optical properties associated with perfectly aligned angles and facets.

We reject over 98 percent of diamonds and only those Lydia would choose to wear herself are destined to become an LMK Diamond.™