Guru Diam is a trade-only wholesale jewellery and diamond supplier for UK jewellers, retailers, designers and manufacturers, shipping from New York. We stock 10,000+ IGI and GIA certified diamonds, natural and lab-grown, alongside calibrated melee, matched pairs, fancy colours, antique cuts and 3,000+ finished jewellery pieces ready to ship. Our custom jewellery service delivers a 3D CAD in 24 hours with no minimum order. Orders confirmed before 6 PM New York time (late evening in the UK) ship the same day, and international delivery typically takes 3–4 business days.
This page is for the UK trade: independent jewellers on the high street, designers and workshops in London's Hatton Garden and Birmingham's Jewellery Quarter, online jewellery brands, and manufacturers who need a dependable source of certified and calibrated diamonds. We do not sell to the public. If you are buying for yourself, ask your local jeweller, who may well source from us.
Below: what we stock, how ordering across the Atlantic works in practice, account opening, payment and returns, and answers to the questions UK buyers ask first. Ready now? Apply for a trade account and an account manager will contact you the same business day.
Wholesale Jewellery UK: Key Facts
| Area | Guru Diam |
|---|---|
| Who we supply | Trade only: jewellers, retailers, designers, manufacturers |
| Certified diamonds | 10,000+ IGI and GIA certified in stock; GCAL offered for lab-grown |
| Range | Natural and lab-grown loose diamonds, melee, matched pairs, fancy colour, antique and old cuts, finished jewellery |
| Finished pieces in stock | 3,000+ ready to ship |
| Same-day dispatch | Orders before 6 PM Eastern (around 11 PM UK time) |
| International delivery | Typically 3–4 business days |
| Minimum order | None |
| Custom jewellery | 24-hour CAD; finished 4–6 working days after approval |
| Account approval | Same business day if submitted before 4 PM Eastern (around 9 PM UK) |
| Returns | 14-day free return on stock items, international orders included |
Why UK Jewellers Source Diamonds From New York
The UK has one of the oldest jewellery trades in the world, and London and Birmingham both have deep local supply. So why buy from New York? Usually for one of three reasons: a client wants something the local market does not have in stock that week, a workshop needs calibrated melee in volume, or a brand wants one supplier that can provide the diamonds and manufacture the finished piece.
Guru Diam operates from 36 West 47th Street in New York's Diamond District and holds a large certified inventory on hand. For UK buyers that means:
- Range in stock today. 10,000+ certified diamonds and 3,000+ finished pieces, rather than diamonds that have to be found first.
- A full working day to order. Our 6 PM Eastern same-day cut-off is around 11 PM in the UK, so you can confirm an order at the end of your trading day.
- Diamonds and manufacturing on one account. Centre diamond, matched side diamonds, melee and the finished setting from the same supplier.
- Delivery typically in 3–4 business days after same-day dispatch.
Ordering Across the Atlantic: How the Time Zones Work
The UK is five hours ahead of New York for most of the year. New York's working day begins around the middle of the UK afternoon, which gives a useful overlap:
| UK time (approximate) | What happens in New York |
|---|---|
| Morning | Messages sent now are waiting when the New York desk opens |
| Early to late afternoon | New York is open: live calls, WhatsApp and quotes in real time |
| Around 9 PM | 4 PM Eastern: trade account applications submitted before now are approved the same business day |
| Around 11 PM | 6 PM Eastern: same-day dispatch cut-off for in-stock items |
Because the US and UK change their clocks on different dates, the gap is four hours for a few weeks each spring and autumn. Your account manager will always confirm cut-off times on a live order.
Lab-Grown Diamonds Wholesale UK
UK demand for lab-grown diamonds has grown fast, from engagement rings to fashion pieces, and jewellers now need a supplier who can provide them consistently in the shapes and sizes clients ask for. We stock lab-grown diamonds in all popular shapes and sizes with IGI grading, and GCAL certification is also offered for lab-grown. Our lab-grown production is mostly CVD, with some HPHT.
Typical UK requests include:
- Oval, round, emerald, pear and elongated cushion centres from 1 to 5 carats
- Diamonds in exact length-to-width ratios for a design
- Larger certified lab-grown centres for statement pieces
- Diamonds sourced or cut to a client's specification when they are not in stock
See the full range on our lab-grown diamonds page, and our guide to sourcing GIA and IGI certified lab-grown diamonds wholesale.
Natural diamonds
We also supply natural diamonds for clients who ask for them. Browse certified natural diamonds and natural melee. Natural matched pairs are made to order.
Calibrated Melee for UK Workshops
Workshops in Hatton Garden and the Jewellery Quarter set a lot of small diamonds, and the quality of a pavé band or a tennis bracelet depends on how closely those diamonds are calibrated. Our melee is calibrated to ±0.05–0.10 mm, and our lab-grown melee is CVD Type IIa. You order by millimetre size, so a design calling for 1.1 mm, 1.3 mm and 1.5 mm gets exactly those sizes, ready for the setter.
Calibrated melee suits pavé, halos, eternity bands, clusters and tennis work. See sizes on our wholesale melee page, or read about calibrated melee for pavé, tennis and eternity work.
Matched Pairs, Fancy Colours and Antique Cuts
Matched pairs are matched to ±0.1–0.2 mm and within about one colour grade, for stud earrings and three-stone side diamonds that look balanced once set. Lab-grown pairs come in all shapes; natural pairs are made to order.
Fancy colour diamonds come in seven colours: black, blue, brown, green, pink, red and yellow.
Antique and old cuts are a strength for UK jewellers working in vintage and heritage styles. We carry so many antique cuts, including Old Mine and Old European cut diamonds. See our antique and fancy colour wholesale page and our guide to antique-cut lab-grown diamonds wholesale.
Finished Wholesale Jewellery
We keep 3,000+ finished jewellery pieces ready to ship, with D–F colour and VVS–VS clarity diamonds and IGI certification.
| Category | What is available |
|---|---|
| Tennis bracelets | 2–32 ct total weight; 7-inch standard always in stock; other lengths made to order |
| Tennis necklaces | 17-inch standard; 16–22 inches made to order; straight-line up to 90 ct, graduated up to 55 ct |
| Stud earrings | All shapes, up to 10 ct total weight in stock; push-back or screw-back; 2 ct total weight and up IGI certified |
| Engagement rings | Solitaire, three-stone and halo; US size 7 standard in stock |
| Eternity and wedding bands | Full and partial eternity in 14K and 18K gold and platinum |
| Mountings and semi-mounts | Ready for your own centre diamond |
Metals are 14K and 18K gold (yellow, white and rose) and platinum. White gold is always rhodium plated, the default finish is high polish, and findings are solid gold in the piece's karat. Ring sizes are quoted in US sizes, so state the size system on every order; our ring size chart is a useful reference. Browse the range on our wholesale jewellery page.
Custom Jewellery Manufacturer for UK Jewellers and Brands
Our custom jewellery service lets UK jewellers and brands offer custom work without adding bench capacity. You keep the client and the margin; we build the piece.
- Send the brief. A sketch, photo or description with metal, centre diamond and finger size.
- Approve the 3D CAD. The render arrives within 24 hours. Nothing is cast until you approve it.
- Production. We cast, set and finish in-house in New York and India with diamonds from our own inventory.
- Delivery. Finished 4–6 working days after approval (complex pieces 2–3 weeks), then shipped internationally, typically arriving in 3–4 business days.
There is no minimum order; you pay per piece. Rush service guarantees delivery in 4 days for an extra charge. We also offer private label production for brands, engraving, satin, matte and hammered finishes on request, and after-sales resizing and repairs. Read our wholesale custom jewellery manufacturer guide and what custom jewellery costs wholesale.
Shipping to the UK
| Stage | Timing |
|---|---|
| Cut-off | 6 PM Eastern (around 11 PM UK time) |
| Dispatch | Same day from New York for in-stock items |
| International delivery | Typically 3–4 business days |
| Custom pieces | 4–6 working days after CAD approval, then shipping |
We ship to jewellers across England, Scotland, Wales and Northern Ireland, from single independent stores to multi-branch retailers and manufacturers. In-stock diamonds and jewellery leave New York the same day they are confirmed before the cut-off, and custom pieces ship as soon as they are finished. See our shipping and returns page for full details.
London, Hatton Garden, Birmingham and Beyond
London and Hatton Garden
Hatton Garden has a dense mix of retailers, dealers and workshops. Many already buy from several sources and come to us for depth: a specific certified lab-grown centre, a run of calibrated melee or a matched pair that is hard to find locally. With the same-day cut-off landing late in the UK evening, a London jeweller can confirm an order after a full day of appointments.
Birmingham Jewellery Quarter
Birmingham's manufacturers and setters order melee and matched pairs by the millimetre. Our ±0.05–0.10 mm melee calibration and per-size ordering reduce sorting time on the bench.
Manchester, Leeds, Glasgow and Edinburgh
Independent jewellers outside London often run smaller teams and rely on outside manufacturing. Our 24-hour CAD and no-minimum custom service lets them take on custom commissions without adding staff.
Online jewellery brands
UK online brands use our API and CSV feed to show our certified diamonds and jewellery on their own websites, and our private label service to manufacture under their own name.
Opening a UK Trade Account
- Apply through the trade partner application.
- Verification. We confirm you are a jewellery business. Applications submitted before 4 PM Eastern (around 9 PM UK time) are approved the same business day; later ones the next business day.
- Account manager. Every account gets a dedicated account manager for sourcing, quotes and order updates.
- Start ordering online, by WhatsApp or phone, through the live order portal for custom work, or via API and CSV feed.
Payment and Returns
We accept wire transfer, ACH, cheque and debit card. Established accounts can apply for credit terms, and memo terms are available for approved accounts. Credit cards are not accepted.
Stock items carry a 14-day free return, and international orders are included. For custom pieces, agree the terms with your account manager before approving the CAD.
A Typical Order From a Hatton Garden Jeweller
On a Monday afternoon in London, a client asks for an emerald-cut lab-grown solitaire with tapered side diamonds in platinum. At 3 PM UK time, New York is just opening, so the jeweller calls our desk, shortlists two IGI-certified emerald cuts and agrees the side diamond sizes on the call.
The jeweller emails a sketch. By Tuesday afternoon UK time, the 3D CAD is back with the platinum weight. The client approves it on Wednesday. The ring is finished 4–6 working days later, shipped from New York, and typically arrives in 3–4 business days. One supplier, one account manager and one invoice covered the centre, the side diamonds and the finished ring.
How to Send a Request That Gets a Fast Answer
| Request | Include |
|---|---|
| Centre diamond | Shape, carat range, colour and clarity range, lab-grown or natural, lab (IGI, GIA or GCAL), ratio if elongated |
| Melee | Millimetre sizes and quantity per size, lab-grown or natural, colour range |
| Matched pair | Shape, size per diamond, colour and clarity range, or the centre's measurements |
| Custom piece | Sketch or photo, metal, US or UK finger size, centre details, finish, engraving |
| Finished jewellery | Stock number, or style, total weight, length or size and metal |
Choosing a Wholesale Diamond Supplier in the UK
| Question | Why it matters | Guru Diam |
|---|---|---|
| What is actually in stock? | Stock ships today | 10,000+ certified diamonds; 3,000+ jewellery pieces |
| Minimum order? | Minimums tie up cash | None |
| Melee calibration? | Saves bench time | ±0.05–0.10 mm |
| Pair matching? | Balance once set | ±0.1–0.2 mm, about one colour grade |
| Custom turnaround? | Clients will not wait weeks | 24-hour CAD; 4–6 working days |
| Delivery? | Speed wins the sale | Same-day dispatch; typically 3–4 business days |
| Returns? | Protects your margin | 14-day free return on stock items |
For a wider view, read our guide to the best wholesale lab-grown diamond suppliers for trade buyers. Our diamond size chart, lab-grown diamond price list and education centre help with quoting and staff training.
Private Label Jewellery for UK Brands
A growing share of UK jewellery is sold by brands that design in-house and outsource production. Our private label service is built for them. You supply the design, or brief us and approve our CAD; we cast, set and finish in-house in New York and India using diamonds from our own inventory; and the finished pieces ship to you under your brand.
Because there is no minimum order, a brand can test a new design with a single piece, then reorder in larger runs once it sells. Finishing options include high polish as standard, satin, matte and hammered finishes on request, and engraving, so each line can carry its own signature look. After-sales service such as resizing and repairs is also available for pieces we make. Typical private label lines include solitaire and three-stone rings, tennis bracelets, stud earrings, eternity bands and pendants, in 14K and 18K gold and platinum.
Connecting Our Inventory to Your Website
Online jewellers and multi-store retailers can pull our certified diamonds and jewellery into their own website or stock system through our API and CSV feed, instead of uploading products by hand. Your dedicated account manager can arrange access once your trade account is open, and custom orders can be followed through our live order portal.
Popular Lab-Grown Shapes for UK Engagement Rings
Shape choice drives most bridal conversations. These are the shapes UK jewellers most often ask us to source, with the points worth checking on the grading report for each:
| Shape | Why clients choose it | What to check |
|---|---|---|
| Round | Classic, maximum sparkle, suits every setting | Cut grade, symmetry and polish |
| Oval | Looks larger per carat, elongates the finger | Length-to-width ratio and any bow-tie effect |
| Emerald | Clean step-cut look, popular for vintage and minimalist styles | Clarity, as step cuts show inclusions more easily |
| Pear | Distinctive, works for solitaires and drop earrings | Symmetry of the shoulders and point |
| Elongated cushion | Soft, romantic outline | Ratio and faceting pattern |
| Radiant | Brilliance with a rectangular outline | Ratio and depth |
| Antique cuts (Old Mine, Old European) | Heritage character for vintage designs | Outline, culet and overall proportions |
Send us the shape, carat range and ratio you want, and we will shortlist certified options from stock, or source or cut to your specification when a diamond is not in stock.
Running a Lab-Grown Bridal Counter Without Deep Stock
Many UK independents want to offer lab-grown bridal without tying up cash in centre diamonds. With no minimum order, a simple model works well:
- Show the styles. Keep a small set of solitaire, three-stone and halo mountings in 18K gold and platinum in the case.
- Show the diamonds. Walk clients through certified diamonds from our live inventory, with grading reports, on a screen in the store.
- Order per client. Confirm the diamond and either set it in your own workshop or have us set it and ship the finished ring.
- Restock as you sell. Reorder tennis bracelets and studs as they move, instead of buying deep stock up front.
The result is a wide choice for the client, a fresh display and cash kept free for the business.
Diamond Quality and Certification
Every certified diamond comes with its IGI or GIA grading report, and GCAL certification is offered for lab-grown diamonds. Reports are listed with each diamond, so your team and your client can check colour, clarity, cut and measurements before the order is confirmed. Diamonds in our finished jewellery are D–F colour and VVS–VS clarity with IGI certification, and studs of 2 ct total weight and up come IGI certified.
About Guru Diam
Guru Diam serves 3,000+ trade accounts and is a member of the Jewelers Board of Trade (JBT). Certified diamonds carry IGI or GIA reports, with GCAL offered for lab-grown. Visiting New York? See inventory at our Diamond District showroom by appointment: book a visit. More about Guru Diam.
FAQ
Do you supply wholesale jewellery to UK jewellers?
Yes. Guru Diam is a trade-only wholesaler that supplies UK jewellers, retailers, designers and manufacturers from New York, with 10,000+ certified diamonds and 3,000+ finished jewellery pieces in stock.
How long does delivery to the UK take?
In-stock orders confirmed before 6 PM Eastern, around 11 PM UK time, ship the same day from New York. International delivery typically takes 3–4 business days.
Is there a minimum order?
No. One diamond or one piece of jewellery is an order.
How fast is a UK trade account approved?
Applications submitted before 4 PM Eastern, around 9 PM UK time, are approved the same business day. Later applications are approved the next business day.
Do you sell calibrated melee to UK workshops?
Yes. Our melee is calibrated to ±0.05–0.10 mm, sold by millimetre size, and our lab-grown melee is CVD Type IIa.
Can you manufacture custom and private label jewellery for UK brands?
Yes. We send a 3D CAD within 24 hours and finish the piece 4–6 working days after approval, with no minimum order. Complex pieces may take 2–3 weeks, and rush service guarantees 4 days for an extra charge. Private label production is available.
What is your return policy for UK orders?
Stock items have a 14-day free return, and international orders, including the UK, are covered.
How do UK accounts pay?
Wire transfer, ACH, cheque or debit card. Established accounts can apply for credit terms, and memo terms are available for approved accounts. Credit cards are not accepted.
Ready to start? Open a trade account, or explore our wholesale hub, lab-grown diamonds, wholesale melee and custom jewellery pages. WhatsApp our diamond desk at +1 (929) 340-3449.
