77 Diamonds

77 Diamonds was founded in London in 2005 by Tobias Kormind and Vadim Weinig, who comes from a family of diamond merchants. It's one of the original online-first diamond jewellers: you search, compare and configure online, then book the showroom to see your shortlist in person. The London showroom opened in 2013 on the second floor of 3 Hanover Square, just off Oxford Circus. There are also UK showrooms in Manchester and Glasgow, and more across Europe.

So, is 77 Diamonds legit? Yes. It has a 4.9 Trustpilot score from more than 6,000 reviews and 4.7 on Google from over 800 for the Mayfair showroom. That's an unusually large and consistent body of reviews for a jeweller.

The diamond search is the reason to use it. 77 Diamonds says it offers a selection of 1.8 million diamonds; when we checked, the live search showed around 286,000 natural stones, with a natural/lab-grown toggle and 360° visuals on many of them. Every stone is certified — but check which lab. The filter covers GIA, IGI and HRD, and most of the listings we saw were HRD or IGI rather than GIA. All three are recognised labs, but if you want to compare prices like-for-like with Hatton Garden, filter for GIA.

Building a ring works in three steps: choose a setting, choose a diamond, and see the finished ring and price. Settings start from about £520 including VAT (October 2026), and the diamond is priced on top. For something fully custom, the bespoke service starts with a deposit, moves through drawings and computer designs, and takes about four to five weeks to make after you approve.

The terms are clear: a 30-day full refund, a free resize within 60 days, a lifetime warranty, and free insured delivery in unmarked packaging. Our view: 77 Diamonds is one of the strongest online-first options in London. You get more choice and more data than any glass cabinet can offer. Book the showroom before you go — visits are by appointment only — and ask for GIA stones if certificate consistency matters to you.