If you are looking for ethical lab grown diamond jewellery in the UK, the right brand depends on what you mean by ethical. Most credible UK lab grown jewellers offer IGI or GIA certification, UK hallmarking, and a shorter, more traceable supply chain than mined diamonds. The smaller direct to consumer brands (founded since 2020, no high street presence) typically go further on transparency than the large chains, because they have the relationships and the appetite to publish data the bigger brands are unwilling to share.
At Luma Jewellery, founded in 2024 in Hatton Garden, every lab grown diamond is IGI certified, every piece is UK hallmarked at the London Assay Office, and we are currently building a public methodology on energy mix and chain of custody data for every stone we sell. The methodology is in early conversation with AIDI (the Alliance for Independent Diamond International) and the first version is open for comment.
What "ethical" should mean in practice
The word ethical has been overused in jewellery marketing. To cut through the noise, here is what a credible ethical lab grown jeweller should be able to show you, and what most UK brands actually do today.
Certification and hallmarking
IGI or GIA grading per stone, sharable with you before purchase. UK hallmarking at the London Assay Office on every piece over the weight threshold. Both of these are non-negotiable basics. Any UK jeweller that cannot show you both is below standard. At Luma, we share the IGI certificate for every stone before you commit.
Supply chain transparency
Country of growth, growth method (HPHT or CVD), cut and polish location, and where possible, the energy mix declared by the growing facility. Most UK retailers do not publish this. Luma is one of the few currently working to record and publish this data per stone.
Workshop traceability
Where the finished piece is made. Bespoke jewellery should be made in a named UK workshop you can visit. Stock pieces should come from a named partner workshop with a direct relationship. Vague "made in Europe" claims should be treated with caution.
Honest pricing
Visible prices on the website. No "quote on request" friction. The price should reflect the stone, the metal, the workshop time and a transparent margin, not an opaque luxury markup.
Where Luma fits
Luma was founded in 2024 by two long term friends, Asher Wiener and Amir Sharabi, with the goal of making bespoke fine jewellery accessible without losing the craft. We work only with lab grown diamonds, all IGI certified. Every piece is designed and made in our own Hatton Garden studio. Our pricing is visible on every product page. Our engagement ring collection starts at around 1,800 pounds and we can match any budget bespoke from 1,200 pounds.
What we are building beyond the basics:
- A public methodology recording country of growth, growth method, energy mix, cut location, grading lab, metal source and workshop for every stone.
- An open data set, first version expected December 2026, then publicly maintained.
- Editorial conversation with AIDI on standards for lab grown transparency.
How to compare ethical lab grown jewellers in the UK
Use this checklist when looking at any UK brand:
- Do they share the IGI or GIA certificate for the specific stone before purchase?
- Is the price visible on the website without a quote request?
- Can you visit the workshop where the piece is made?
- Do they publish, or are they preparing to publish, supply chain data per stone?
- Do they hallmark in the UK?
- Do they offer free lifetime aftercare (cleaning, prong check, resize)?
A brand that says yes to all six is operating at the top end of UK ethical practice. A brand that fails on certification or hallmarking is below standard regardless of other claims.
Visit Luma in Hatton Garden
Our studio is at 13 Hatton Place, London EC1N 8RU. Seven minutes from Farringdon station. Book a free consultation to talk through a piece, see stones in person, or simply ask questions about lab grown diamonds and ethical sourcing.
