Lab-grown and synthetic gemstones from China
Synthetic and reconstructed stones from China, including CVD and HPHT lab-grown diamonds, cubic zirconia, synthetic sapphire and ruby, moissanite and piezoelectric quartz, pay 0% UK duty on all five lines of heading 7104, with no anti-dumping duty. Buyers check the grading report against the stone, clear disclosure that it is laboratory-grown, and cut, colour and clarity.
Lab-grown diamonds, cubic zirconia, synthetic sapphire and moissanite from China pay 0% UK duty. Grading, disclosure and rough diamond rules explained.
0% duty
Read from the UK Trade Tariff on 27 September 2026, heading 7104 covers synthetic or reconstructed precious or semi-precious stones, whether or not worked or graded but not strung, mounted or set. All five leaves, piezoelectric quartz (7104 10 00 00), unworked diamonds (7104 21 00 00) and other stones (7104 29 00 00), and worked diamonds (7104 91 00 00) and other stones (7104 99 00 00), carried 0% on goods from China, with no anti-dumping measure, no registration and no suspension.
Natural diamonds are heading 7102, and stones set in jewellery are classified as jewellery (see our jewellery guide); confirm the commodity code.
| Goods | Commodity code | Duty | Anti-dumping duty on China |
|---|---|---|---|
| Piezoelectric quartz | 7104 10 00 00 | 0% | None |
| Diamonds, unworked or simply sawn or roughly shaped | 7104 21 00 00 | 0% | None |
| Other stones, unworked or simply sawn or roughly shaped | 7104 29 00 00 | 0% | None |
| Diamonds, other (such as cut and polished) | 7104 91 00 00 | 0% | None |
| Other stones, other (such as cut cubic zirconia) | 7104 99 00 00 | 0% | None |
Rough diamonds and disclosure
GOV.UK guidance says rough diamonds can only be imported to and exported from countries in the Kimberley Process Certification Scheme, or goods may be seized, and the UK takes part as an independent participant. That scheme covers rough natural diamonds, so make sure invoices, packing lists and grading reports describe lab-grown stones as laboratory-grown.
Sell lab-grown diamonds and other synthetic stones under names that make clear they are synthetic, and keep the grading report with each stone.
Specifying stones
Specify the material and growth method, shape and cut, carat or millimetre size, colour and clarity grade, the grading laboratory and report number, laser inscription if any, treatments after growth, calibration tolerance for melee, and packing in labelled parcel papers.
Worked duty example
Take a hypothetical order of 200 polished lab-grown diamonds with grading reports, entered under 7104 91 00 00: £40,000 free on board plus £300 of freight and insurance gives a customs value of £40,300. Polished lab-grown diamonds carry no duty, so import VAT of 20% on £40,300, £8,060, is the only tax. A VAT-registered importer normally reclaims it, so the border adds no lasting cost. Step by step: UK import duty and VAT.
Inspection checklist
Reports: match each report number and inscription to its stone, and check weights on a calibrated scale.
Grading: check a sample for colour and clarity against the reports under standard lighting.
Parcels: check counts, sizes and sieve ranges for melee against the order.
What goes wrong
Synthetic stone orders fail on grading and paperwork. Stones are graded more generously than the report, melee sizes are mixed, post-growth treatment is not disclosed, and invoices fail to say the stones are laboratory-grown.
Test samples before shipping. See our quality inspection guide.
Cambridge China Bridge sources lab-grown diamonds and synthetic stones for UK jewellers and watch and industrial buyers, checking the grower and cutter first. See factory verification.
Frequently asked questions
What is the UK import duty on lab-grown diamonds from China?
Read from the UK Trade Tariff on 27 September 2026, lab-grown diamonds under 7104 21 00 00 and 7104 91 00 00 carried 0% from China.
Are lab-grown diamonds in heading 7102?
No. Heading 7102 is natural diamonds; synthetic diamonds are heading 7104.
Do lab-grown diamonds need a Kimberley Process certificate?
The scheme covers rough natural diamonds; describe lab-grown stones as laboratory-grown on every document.
What fails most often?
Grading that does not match the report, mixed melee sizes and undisclosed treatments.