An assay report helps a buyer evaluate the gold content of a tested sample. It does not, by itself, establish who owns a proposed lot, where it originated, or whether the material delivered later is the same material that was sampled. Buyers considering physical gold connected to Congo, Uganda or elsewhere in East Africa should settle the sampling and testing procedure before agreeing to payment terms.
Identify the material the report covers
Start with the lot description. Compare the report’s sample or batch identifier, material type, date and stated weight with the proposed contract and packing records. Ask who collected the sample and whether both parties witnessed it.
A result is only as useful as the sample’s connection to the full lot. The LBMA’s physical market guidance explains that accurately determining a gold bar’s fineness requires a representative sample and appropriate analysis. A test of one small piece should not automatically be treated as the result for an unexamined shipment.
Read the result and method together
Check how the laboratory states fineness, which analytical method it used, and whether the report identifies uncertainty or limitations. Fire assay is an established method, but the suitability of a particular method depends on the material and sampling conditions. ISO 11426:2021, for example, describes a cupellation method for determining gold in material considered homogeneous; citing that standard does not mean a particular transaction or laboratory is certified under it.
Ask the proposed receiving refinery or an independent assayer which method it will accept. Agree whether settlement will rely on an initial test, a witnessed test at handover, or a final receiving-refinery result.
Agree what happens if results differ
A contract should identify the testing location, who selects the laboratory, how samples are divided and sealed, who pays for testing, and the process for resolving a disputed result. Record the lot’s identifiers and custody at each handover. This gives the buyer and seller a way to connect the final result to the material actually delivered.
The assay process should sit alongside checks on ownership, source and supply-chain records. The OECD’s mineral due diligence guidance addresses risks in mineral sourcing that a purity test alone cannot resolve.
Before making a commitment, buyers can send their product and destination requirements and arrange their own independent technical and legal review. See also our buyer due diligence checklist.