A lab grown diamond is a diamond. It has the same chemical composition, crystal structure, hardness and optical properties as a mined diamond — it simply grew in a reactor rather than in the earth. For wholesale buyers, the questions that matter are growth method, certification economics and price direction.
How they are made
CVD (chemical vapour deposition) grows diamond from a carbon-rich plasma onto a thin diamond seed plate. It scales well, produces mostly colourless material in the commercially valuable D–F range, and dominates volume supply.
HPHT (high pressure high temperature) reproduces natural diamond-forming conditions, dissolving carbon in a metal flux so it crystallises on a seed. It yields excellent clarity but lower throughput, and is generally used for larger, higher-value stones.
CVD vs HPHT for buyers
| Factor | CVD | HPHT |
|---|---|---|
| Typical colour | D–F, occasional brown tint if unsorted | D–F, E–F typical |
| Typical clarity | VS–SI common | VVS–VS common |
| Post-growth treatment | Common for colour improvement (must be disclosed) | Less common |
| Relative price | Lower at volume | Higher, especially above 1 ct |
| Best commercial use | Melee, 0.3–2 ct rounds, fashion lines | Certified centre stones, bridal |
Reading an IGI report
- Report number — verifiable in the laboratory's online lookup, and inscribed on the stone's girdle.
- Measurements — millimetres, not just carat weight. Always verify with callipers.
- Colour and clarity grades — assigned by the laboratory, not by the seller.
- Polish and symmetry — the cut-quality indicators that most affect appearance.
- Growth method and treatment status — legally relevant in several markets and often omitted in cheap quotations.
- Fluorescence — blue fluorescence can affect appearance in some lighting.
What moves the wholesale price
- Size. Price per carat rises steeply above 1.5 ct because fewer large roughs survive cutting.
- Colour and clarity. Moving from G/VS to D/VVS at the same size can add 40–80%.
- Certification. A certified 1 ct stone can carry a 15–25% premium over an uncertified equivalent.
- Growth method. HPHT typically carries a modest premium, most visibly above 1 ct.
- Market timing. Because supply is manufactured, prices have historically drifted down rather than up — structure agreements with a price-review clause.
Disclosure and market rules
Lab grown diamonds must be disclosed as lab grown in most consumer markets, and the terminology is regulated in several. Your supplier's invoice is your evidence trail: it should name the goods accurately, state the growth method where known, and list certificate numbers per line. Buyers who cannot produce that paper are exposed at retail.
Specification template
Stone: lab grown diamond, CVD, 1.20–1.30 ct, F colour, VS1 clarity, round brilliant, excellent polish and symmetry, IGI certified with girdle inscription; metal: 14K white gold, 3.2 g ±5%; setting: six-prong; MOQ 10 pcs; lead time 12–18 days.
Parcel buying for lab grown diamonds
Loose stones are often bought as parcels — groups sold together at a blended price per carat. Always request the breakdown by size band, colour and clarity with counts per band, then calculate the effective price of the stones you can actually set. A parcel that looks cheap per carat may contain a large share of grades you cannot use, which changes its true cost. For matched sets — three-stone rings, earring pairs, bracelet runs — sort by millimetre size first, then colour on white paper in daylight, then clarity under magnification.
Matching a reorder months later
- Retain a physical reference stone for every grade you buy, labelled and stored together.
- Record the growth method and colour range on your own purchase order, not just the certificate number.
- Confirm with your supplier that the same stone source will be used for the reorder.
- Buy sufficient quantity for the season rather than topping up monthly, so a single production batch covers the run.
Documentation for retail
If your customers ask for provenance, the documents you can hand over are the certificate, the commercial invoice naming the goods as lab grown, and any material declaration for the metal. Buyers in markets with disclosure rules should ensure the invoice states the growth method, and should keep certificate copies on file for at least the life of the retail sale. Your supplier's paperwork is your evidence trail.
Who buys lab grown diamonds at wholesale
Three buyer groups order lab grown diamonds from our bench, and each reads the specification sheet differently. Bridal retailers centre on certified centre stones above 0.5 ct equivalent, where colour, clarity and a matching certificate drive the sale. Marketplace and gift brands buy calibrated melee and 0.3-1 ct rounds in volume, where consistent size and a stable per-carat price matter more than a top grade. Manufacturers and setters source matched parcels for their own production runs, sorting by millimetre size before colour and clarity.
Match your grade mix to your channel before you order. A bridal line can carry D-F, VS-VVS certified stones; a fashion or marketplace line usually sells G-J, VS-SI at a lower price point. Mixing both in one parcel often leaves the buyer holding the grades their channel cannot move.
Inspection checklist before you accept a parcel
- Match every certificate number to the girdle inscription and the report lookup before unpacking the stones.
- Measure each centre stone with callipers and record the millimetres; do not rely on carat weight alone.
- Compare colour on white paper under daylight, then under a colour-corrected lamp, and note any brown or grey modifier.
- Check clarity under 10x magnification and separate eye-clean stones from those with visible inclusions.
- Record fluorescence and any post-growth treatment on your own sheet, so the reorder matches the first run.
Wholesale lab grown diamond ordering questions
What MOQ applies to a first diamond order?
First orders start at MOQ 10 pcs for finished jewellery and a per-carat minimum for loose stones. Sample pieces can be supplied before a production run so you can verify cut, colour and setting quality on hand.
How long does a diamond production run take?
Lead time is typically 12-18 days after approval of the sample and the specification sheet, with matched parcels held for reorder. Larger centre stones and custom settings may add a few days for setting and polishing.
Can a reorder match the first shipment?
Yes, when you retain a reference stone and record the growth method, colour range, clarity and size band on your purchase order. We match the retained standard rather than a new production batch.
Which certificates travel with the stones?
Centre stones above 0.5 ct equivalent ship with an IGI report and girdle inscription; melee and volume lines carry GRA or internal grading where a certificate is not requested. The invoice names the goods as lab grown and lists certificate numbers per line.
Choosing shape and carat for a wholesale line
Round brilliants remain the bridal standard and are the safest first buy for a new account; oval, pear and cushion carry an elongation or vintage look that suits fashion and gift lines. Most wholesale centre stones fall between 0.5 and 1.2 ct equivalent, with 1.5 ct and above reserved for custom bridal and special orders. Match the shape to your existing ring and earring settings rather than buying a shape your bench cannot set.
| Shape | Typical use | Best channel |
|---|---|---|
| Round | Solitaire rings, studs, melee | Bridal, marketplace |
| Oval / pear | Elongated rings, pendants | Fashion, bridal |
| Cushion | Vintage rings, halo sets | Premium retail |
Keep at least two sizes per shape for fast reorder, and hold a small melee stock for repairs and accent settings. Buyers who overstock one size band usually face slower turnover, while a narrow range across three sizes keeps both ring and earring orders covered. Record the growth method and certificate grade on every line, so a repeat order can be matched against the first shipment rather than a fresh sample.
Building a diamond programme with our factory
Send your stone list, design files or reference samples and we return a factory quotation built from cost components rather than a distributor price list. Volume tiers apply above 50 and 200 pieces, with a 30% deposit and a named account manager for repeat accounts. You can browse our lab grown diamond jewellery and lab grown diamond supply range, or request a wholesale quote with your target grades and quantities.