Preparing Gold for Independent Testing Before a Sale

When a seller and buyer disagree about purity, the problem is often not simply the analytical instrument. It may be whether the sample was representative, identifiable and protected from substitution. Preparing for independent testing means agreeing the purpose of the result before the sample is collected.

Describe the lot correctly

Record the form of material, approximate mass and the number of bars, parcels or containers. Doré, refined bullion, scrap and ore differ in composition and sampling needs. A photograph is useful for identification but does not replace a physical inventory or analytical result.

Choose a method for the question

XRF analysis can screen elemental composition on suitable exposed surfaces and may help identify unusual alloying elements. It cannot, by itself, certify the internal composition of a heterogeneous bar. Ultrasonic gold testing can help investigate internal structural anomalies in suitable solid objects but does not determine gold purity. Density testing provides a physical consistency check, not a complete composition assay.

A properly prepared representative sample tested by Fire Assay may provide a stronger quantitative basis for gold content. The laboratory should advise on preparation and method suitability for the material, not simply select whichever test sounds most sophisticated.

Agree sampling and witness arrangements

Decide whether the lot will be homogenised or sampled in sections, who performs sampling, who witnesses it, how samples are divided and sealed, and whether an independently held referee sample is needed. Record chain of custody from collection to receipt. If a seller cannot permit destructive sampling, discuss the limitations and whether alternative screening can answer a narrower question.

Ask what the report will include

A useful laboratory enquiry should ask for sample identity, reported method, units, results, relevant limitations and how the result can be linked back to the inspected material. A report that states high purity for one submitted chip cannot automatically prove a larger lot meets the same specification.

Connect assay evidence with price negotiations

The seller should ask how the buyer intends to use the result to calculate payable gold, refining terms and settlement. A clear sampling agreement helps prevent a disagreement later. For the pricing framework, read How to Use an Assay Report When Negotiating a Gold Price.

Arrange a suitable scope

Bilex's primary service is independent gold testing and verification. Describe the material, approximate quantity, location and commercial question when requesting an appointment. Bilex should explain the agreed analytical scope before work starts, including any method limitations and sample-handling requirements.