Rough diamond imports must comply with the Clean Diamond Trade Act, which implements the Kimberley Process Certification Scheme. Each shipment requires a government-validated Kimberley Process Certificate accompanying the goods, and the shipment must be sealed in a tamper-evident container. CBP enforces these requirements at entry.

Industrial diamonds (710221, 710229) are those used primarily for drilling, cutting, grinding, or abrasive applications due to their quality characteristics. Nonindustrial (gem) diamonds (710231, 710239) meet the clarity, color, and size standards for jewelry use. The classification follows the stone's quality and intended use, and borderline cases may require a CBP ruling.