Bulk loose lab‑grown diamonds (rough / cut‑polished, unmounted) imported into the United States are governed by CBP (Customs and Border Protection), US HTS tariff classification, FTC Jewelry Guides, and US sanctions rules. Kimberley Process certification is NOT required for lab‑made diamonds; Kimberley controls only natural rough mined diamonds.
1. HTS Classification & Tariff Duty
Lab‑made diamonds fall under Chapter 71 (synthetic/reconstructed precious stones), separate from natural diamond HTS codes.
- HTS 7104.21.00.00: Rough / sawn lab‑grown diamonds (un‑polished bulk parcels)
- HTS 7104.91.20.00: Cut & polished bulk lab‑grown gem diamonds (jewelry‑grade loose stones)
Duty note: General duty rate is 3%, duty‑free under many US trade‑agreement special rates; Column‑2 punitive rate is 30% for goods from sanction‑target jurisdictions.
Mis‑classifying lab‑grown stones under natural‑diamond HTS codes will trigger customs holds, audits, or penalties, even with zero‑duty treatment.
2. Mandatory Customs Documentation for Bulk Shipments
For bulk wholesale consignments (multiple‑carat parcels):
- Commercial Invoice
- Explicitly state “Lab‑Grown / Laboratory‑Created Diamonds”; specify production method: CVD or HPHT.
- Break‑down total carat weight, piece count, unit value, total shipment value.
- Declare country‑of‑origin (where the diamond was synthesized/grown), not just country of export.
- Packing List: itemize parcels, carat ranges, counts.
- Air Waybill / Ocean Bill of Lading.
- Grading reports: IGI / GIA lab‑grown certificates for representative stones within bulk lots (CBP may request verification of lab‑origin claim).
- Self‑certification for Russian‑origin sanctions: Since Sep 1 2024, non‑industrial diamonds ≥0.5 ct require a signed statement certifying goods are not produced/manufactured in the Russian Federation, even if transformed in third countries.
- No import license is required for lab‑grown diamonds into the US.
Kimberley Process Certificate is not needed for lab‑made rough or polished diamonds — KPCS applies exclusively to natural rough diamonds under the Clean Diamond Trade Act.
3. FTC Federal Trade Commission Rules (critical for B2B bulk imports)
FTC Jewelry Guides govern labeling and description, even for inbound wholesale bulk shipments before retail resale:
- Must clearly identify goods as lab‑grown / laboratory‑created / man‑made diamond.
- Prohibited deceptive shorthand: do not use only “diamond” without qualifier; avoid “cultured”, or language implying mined‑diamond rarity.
- Bulk invoices, manifests, internal inventory records must reflect lab‑made origin, to avoid downstream misleading‑marketing liability for the US importer.
- “Synthetic” is technically acceptable but FTC prefers “lab‑grown” for gem‑diamond trade to prevent consumer confusion with simulants.
4. Shipping, Risk & Customs Enforcement
- High‑value bulk diamond shipments require marine‑cargo insurance explicitly naming “lab‑grown diamonds”; standard courier liability caps are very low (≈$100 per package) and insufficient for gem‑stone parcels.
- CBP may physically inspect bulk parcels, require lab verification to confirm stones are synthetic (not natural diamonds mis‑declared). Penalties for mis‑declaration can include seizure, monetary fines, and increased future inspection rates.
- Post‑August 2025: US de‑minimis low‑value shipment exemption no longer applies; all bulk diamond shipments require full formal customs entry, regardless of value.
- Use a customs broker with gem‑stone / diamond import expertise for bulk lots.
5. Record‑Keeping Obligations
US importers must retain all import documents (invoices, certificates, origin statements, sanction self‑certifications) for 5 years post‑import for CBP audit purposes.
Quick Compliance Checklist for Bulk Lab‑Made Diamond US Import
✅ Correct 10‑digit HTS code (rough 7104.21.00.00 / polished 7104.91.20.00)
✅ Invoice clearly marks “Lab‑Grown”, lists CVD/HPHT method, origin, total carat & value
✅ Russian‑origin sanction self‑cert for stones ≥0.5 ct
✅ No Kimberley Process certificate (lab‑grown are exempt)
✅ Retain supporting lab grading documentation
✅ Formal customs entry (no de‑minimis shortcut)
✅ All‑risk cargo insurance for high‑value bulk parcels
Disclaimer: This is general trade guidance; always confirm HTS classification and current sanction rules with your licensed US customs broker prior to shipment.