ISO 6893:2024

Overview

ISO 6893:2024 - Jewellery and precious metals - Inspection of batches of small diamonds defines standardized terminology, classification and test methods for inspecting batches of unmounted, polished colourless small diamonds with individual mass ≤ 0.25 ct. The standard is intended for batch inspection (often by sampling) and explicitly excludes use for single-diamond certification, fancy coloured, synthetic, treated or assembled stones. ISO 6893:2024 complements ISO 24016 and ISO 18323 to harmonize quality assessment across the jewellery and watchmaking supply chain.

Key topics and technical requirements

ISO 6893:2024 organizes practical inspection work into clear technical areas and procedures, including:

• Terminology and classification - common definitions for batch characteristics and grading attributes to ensure consistent communication.
• Batch specifications and inspection principles - defining homogeneity requirements and the scope for sampling-based inspections.
• Authentication - procedures to confirm diamonds are natural, unmounted and appropriate for batch inspection.
• Sieving and mass estimation - methods to sieve, count and weigh diamonds to estimate total mass or batch size safely and accurately.
• Mass and dimensional measurements - weighing procedures, expression of batch mass, traditional and automated measurement methods (e.g., profile projector, automated dimensioning).
• Sampling plans and inspection strategy - guidance on drawing samples, sampling plans, multiple-criteria inspection and decision rules suitable for large batches.
• Cut-related attributes - assessing shape, proportions, polish and symmetry with test methods and grading descriptors for homogeneous and inhomogeneous batches.
• Colour, fluorescence and clarity testing - visual and instrumental testing (including spectrometry for fluorescence) and standardised grade descriptions.
• Reporting - required content for a test report documenting inspection results and conformity.

(Informative annexes include figures for round brilliant cut and a sampling-control flowchart.)

Practical applications

ISO 6893:2024 is practical for:

• Quality control in diamond trading, manufacturing and supply-chain acceptance testing.
• Jewellery and watchmaking companies that purchase small diamond batches for setting and assembly.
• Independent gemological laboratories developing batch inspection services.
• Procurement, inspection and compliance teams seeking consistent grading and dispute reduction.
• Customs, certification or logistics partners handling high-volume small-diamond consignments.

Benefits include harmonized inspection methods, reduced commercial disputes, reliable batch descriptions, and increased consumer confidence in jewellery products.

Related standards

• ISO 24016 (grading of polished diamonds over 0.25 ct)
• ISO 18323 (diamond grading terminology and communication)

For full test procedures, sampling tables and grading definitions consult the official ISO 6893:2024 publication available from your national standards body or www.iso.org.