Overview
ISO 11596:2021 - Jewellery and precious metals - Sampling of precious metals and precious metal alloys - defines standardized procedures for taking representative samples of entirely metallic precious metals and precious metal alloys. The standard is intended for use on raw materials, semi‑finished products and finished jewellery articles to determine precious metal content and to assess homogeneity prior to assaying.
Key topics and requirements
- Scope and applicability: Sampling applies only to entirely metallic materials (raw material, cast/wrought products, components, finished articles). Coatings must be removed before sampling.
- Sampling objective: Produce representative samples suitable for determination of precious metal content and homogeneity assessment.
- Sampling methods covered: dip sampling of molten alloy (pin and bead/button variants), drilling, scraping, cutting, sawing/filing and lot/sample splitting. Annex A provides guidelines for typical products.
- Tools and contamination control: Lists non‑contaminating tools (drilling rigs, quartz/graphite tubes and ladles, assay shears, polished sample splitters, etc.) and requires cleaning/maintenance to avoid contamination.
- Sample selection and subdivision: Samples should be taken from defined sampling positions to evaluate homogeneity; powders and casting grain require appropriate lot splitting. Where proven homogeneous, reduced sampling schemes may be permitted.
- Sample quantity guidance: For raw/semi‑finished materials (bars, ingots, sheet, rod, wire, casting grain) each prepared sample should generally weigh at least twice the amount needed for a full assay in duplicate (where practical). For component parts and finished products provide sufficient material for one full assay in duplicate.
- Surface preparation: Remove dust, oil, grease and any coatings with non‑residue cleaners; avoid chlorinated hydrocarbons and harmful solvents.
- Retention and traceability: Procedures for retaining and handling samples to preserve integrity for analysis.
Practical applications and users
ISO 11596:2021 is essential for:
- Assay laboratories and refiners performing precious metal content analysis.
- Jewellery manufacturers and quality control teams verifying alloy composition and homogeneity.
- Regulatory bodies, hallmarking offices and customs authorities requiring standardized sampling for conformity assessment.
- Metallurgists and procurement teams inspecting raw materials (powder, grain, ingots) and batch lots.
Using ISO 11596 improves assay reliability, reduces contamination risk, and supports consistent quality control and dispute resolution in the precious metals supply chain.
Related standards
- ISO 3954 (Powders for powder metallurgical purposes - Sampling) is cited for lot/sample splitting techniques.
- The standard’s bibliography lists additional standards for determination of precious metal contents and sampling guidance for production control or lot inspections. Note: alternative assaying techniques may require different sampling procedures.
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