An assay certificate is the single most important document in a gold transaction. It tells you how much gold you are actually paying for. It is also one of the most commonly forged documents in the trade.
What a genuine certificate shows
- The laboratory: full name, address, contact details and accreditation.
- A unique certificate and sample number that the lab can confirm when you contact it.
- Date of testing and of issue.
- Description of the material: doré bar, granules, dust or refined bar, with any bar markings.
- Gross weight of the material tested.
- Fineness or purity of gold, usually in parts per thousand (for example 920.5) or as a percentage, often with silver and other elements.
- Fine gold content: gross weight multiplied by gold fineness. This is the figure you are paying for.
- Method used, and the signature of the responsible analyst.
A worked example
A 1,000 g doré bar assayed at 920.5 fineness contains 920.5 g of fine gold. Price is normally set on fine gold content, less refining and other charges, not on gross weight.
Testing methods are not equal
Fire assay is the long-established reference method for gold purity: a sample is melted, separated and weighed. X-ray fluorescence (XRF) is fast and non-destructive but mainly reads the surface, so it can be fooled by plating or a bar with a different core. For significant purchases, a fire assay from an independent lab is the standard to insist on.
Warning signs
- The certificate comes from a lab the seller chose and you cannot independently contact.
- Unrefined doré is described at refined purity (99.9%).
- Weights or bar markings do not match the material in front of you.
- Only XRF results are offered for a large lot.
- Certificate numbers, logos or signatures look copied or inconsistent.
In Ghana specifically
Under the Gold Board Act, 2025, GoldBod is the official assayer, as well as buyer and exporter, of gold from licensed small-scale mining. An assay certificate attached to small-scale gold offered to you privately for export should be treated with great caution.
Sources
- Graphic Online: GoldBod now sole buyer, seller, assayer and exporter of ASM gold (14 April 2025)
- Mining Weekly (Reuters): Ghana bars unrefined artisanal gold doré exports from September 1
This article is for information only and is not legal, tax or investment advice. Rules and figures change; confirm the current position with the relevant authority or a qualified adviser before acting. Image: illustration (AI-generated).
