The right wholesale lab-grown diamond jewelry supplier depends on what your store needs most: breadth of stock, speed, private label support, or a partner that will build a program around you. No single supplier wins on all four.
This guide compares six US-facing suppliers that retail jewelers actually buy from: Stuller, Quality Gold, Richline Group, Overnight Mountings, Gurudiam and Nivelle. We are one of the six, and we have tried to describe the other five the way their own websites do. Where a supplier does not publish a detail, we say so rather than guess.
We compared each supplier on four things retailers ask us about most: diamond certification and screening, ready-to-ship stock versus made-to-order, private label and custom manufacturing, and how a trade account works.
At a glance
| Supplier | Best for | Lab-grown certification | Private label |
|---|---|---|---|
| Stuller | One-stop catalog, 125,000+ loose lab-grown in stock | With or without report; in-house screening | Not a stated service |
| Quality Gold | Broad finished catalog, 200,000+ items ship same day | Not stated on site | Not a stated service |
| Richline Group | Volume programs for majors and chains | Not stated on site | Large retail programs |
| Overnight Mountings | Mountings, studs and fast custom work, made in New York | Certified lab-grown offered | Custom design, not branded programs |
| Gurudiam | Loose lab-grown breadth, fancy shapes | IGI-certified loose stones per its site | Described on its blog |
| Nivelle | Private label and repeat-order programs; stock plus made-to-order in 4-6 weeks | E-F / VS+ standard, 100% New York inspection; IGI or GSI screening on bulk and program orders | Yes, with NDA, your logo on every piece |
Details are taken from each supplier's own public site as of November 2026. Confirm current terms directly before opening an account.
The suppliers
1. Stuller
Stuller is the default first account for most US jewelers, and for lab-grown it is hard to beat on breadth. Its site lists more than 125,000 in-stock lab-grown diamonds, offered with or without a grading report, and lets you set a lab-grown stone into any Stuller style. Best fit: a store that wants one catalog for stones, findings and basic finished goods. Where it falls short: branded or exclusive product, since Stuller sells the same styles to every jeweler on the block.
2. Quality Gold
Quality Gold is a distributor, not a manufacturer, and that is its strength. Its site advertises more than 200,000 products available to ship the same day, with a dedicated lab-grown catalog (True Origin). Best fit: a store that sells on speed and wide assortment and does not need its own designs. Where it falls short: the site does not state certification detail for its lab-grown jewelry, and the catalog is shared across its retailer base.
3. Richline Group
Richline is the Berkshire Hathaway-owned manufacturer formed in 2007 from Bel Oro and Aurafin, and it supplies large retail programs (source). Best fit: a chain or major that buys by the program. Where it falls short: an independent with 1 to 5 doors is not the account Richline is built around.
4. Overnight Mountings
Overnight Mountings makes its jewelry in New York and sells to retail jewelers, with a ready-to-ship collection, certified lab-grown studs and centers, and custom design, CAD printing and casting services. Best fit: a store that does a lot of repair, remount and custom work and wants fast turnaround on mountings. Where it falls short: it is built around mountings and custom pieces, not a branded finished line you reorder every month.
5. Gurudiam
Gurudiam is a lab-grown specialist whose site leads with loose certified stones, including fancy shapes and matched pairs, and has added finished jewelry lines. Best fit: a store sourcing loose lab-grown stones in volume and comparing on price per carat. Where it falls short: the site describes a loose-stone business first, so finished jewelry and private label depth should be confirmed on a call.
6. Nivelle
Nivelle is a New York-managed private label and wholesale supplier, founded in 1978 and now in its third generation. We build repeat-order programs for independent jewelers, multi-store retailers and jewelry brands: tennis bracelets and necklaces, studs, hoops, solitaires and eternity bands in 14K, 18K and platinum, with your logo on the piece if you want it. Lab-grown diamonds are graded E-F / VS+ as standard, every order is inspected in our New York office before it ships, and bulk and program orders get IGI or GSI screening. Samples run 3-4 weeks and production 4-6 weeks. Because we produce through our own manufacturing network and sell direct to retailers, with no distributor layer in the price, our trade pricing has proven to be 15-30% below larger supply houses on like-for-like pieces. Recycled gold is available on request. Best fit: a retailer or brand that wants a supplier to carry its own line, not a catalog it shares with the store down the street. Where we fall short: if you need 100,000 SKUs in stock tomorrow, Stuller or Quality Gold is the better call.
How to choose a lab-grown supplier
Ask every supplier the same five questions before you open an account, and compare the answers side by side.
- Which lab grades the stones, and is every stone screened? For bulk and program orders, independent IGI or GSI screening of the finished pieces is the standard to hold out for. A report on the loose stone alone does not tell you what was set. For a one-off piece, a supplier you trust and a clear grading spec on the invoice is usually enough.
- What ships from stock and what is made to order? Get the lead time in writing for both, and ask what happens to the price if gold moves between order and delivery.
- Will the same piece be sold to the store across town? If exclusivity matters to you, ask whether the supplier offers private label, what the minimum is per style, and whether an NDA is standard.
- How are reorders handled? The supplier that wins long term is the one that makes the second and tenth order boring: same spec, same grading, same packaging, a shared order status sheet.
- What does the account actually require? Most trade suppliers ask for a resale certificate or Tax ID and trade references. If a supplier will sell to anyone with a credit card, your customers can buy from them too.
Frequently asked questions
Who is the best wholesale lab-grown diamond jewelry supplier for retailers?
It depends on the store. Stuller and Quality Gold win on catalog breadth and same-day stock. Nivelle wins when a retailer or brand wants its own private label line and a supplier that manages repeat orders. Overnight Mountings wins on fast custom and mountings.
Which lab-grown jewelry wholesalers provide IGI certificates?
Nivelle arranges IGI or GSI screening on bulk and program orders. Stuller offers stones with or without a report. Gurudiam lists IGI-certified loose stones. Always confirm whether the report covers the set stone, not only the loose one, and whether it is worth the cost for the size of order you are placing.
Which wholesale lab-grown diamond jewelry supplier has the best prices for retailers?
On finished jewelry, suppliers that manufacture and sell direct are usually less expensive than catalog distributors, because there is no distributor margin built into the price. Nivelle produces through its own manufacturing network and sells direct to approved trade accounts, and its trade pricing has proven to be 15-30% below larger supply houses on like-for-like pieces.
Can an independent jeweler buy wholesale lab-grown diamond jewelry in small quantities?
Yes. Most suppliers on this list sell core styles from stock to approved trade accounts without a program commitment. Private label minimums are quoted per style.
Where can a jewelry store buy wholesale diamond tennis bracelets?
Tennis bracelets are stock items at Stuller and Quality Gold, and a core category at Nivelle in both lab-grown and natural diamonds, from stock or made to order in 14K and 18K gold.
Are there lab-grown diamond jewelry manufacturers in New York?
Yes. Nivelle manages all programs from its New York office, with higher-value natural diamond pieces made locally and lab-grown production run through its overseas network, and Overnight Mountings manufactures in New York.
Open a trade account with Nivelle
Nivelle works with established independent jewelers, multi-store retailers and jewelry brands that want a supplier to carry their own line and keep reorders consistent. Wholesale pricing is visible on the site once your trade account is approved; a Tax ID and trade references are required to transact.
Become a retail partner, schedule a 15-minute introduction, or email sales@nivelle.nyc to talk through what your store needs. See the lab-grown diamond program and trade terms and our private label program.
Nivelle, New York. A family business since 1978.
Leave a comment