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Assaying and Hallmarking Laboratory of NGJA

The internationally accepted Precious Metal Assaying office fully equipped with Modern instruments is located at the Head Office of NGJA in No. 25, Galle Face Terrace, Colombo 03. Assaying and hallmarking of jewellery and issue of certificates are the primary function of the assay laboratory. The issuance of valuation reports for jewellery is done only if requested by the Bank and courts of justice. The Assay Office of NGJA is a Full member of International Association of Assay Offices (IAAO) and an observer member of the Hallmarking Convention of Vienna.

What is Assaying?

A quantitative analysis which, fusion is used to separate precious metals from other alloying metals in a known amount of sample, using approved analytical methods.

 What is Hallmarking ?

Process of stamping precious metal jewellery with series of Logos/marks after passing specified test. Hallmark comprises of Assay Office Mark, mark for metal type, standard mark and Sponsors mark (Responsibility Mark).  

The Convention

The objective of the Precious Metals Convention is to facilitate trade in precious metal articles while at the same time maintaining fair trade and consumer protection justifies by the particular nature of these articles. For that purpose, the Convention has introduced the first international hallmark – the Common Control Mark (CCM) – indicating the precious metal and its fineness.

The Convention enables designated national Assay Offices under the terms of the Convention to apply the Common Control Mark to articles of platinum, gold, palladium and silver and after having tested their fineness in accordance with agreed testing methods.

List of Convention Members (Members and Observe Members)

austria Austria austria Netherlands
austria Cyprus austria Norway
austria Czech Republic austria Poland
austria Denmark austria Portugal
austria Finland austria Slovak Republic
austria Hungary austria Slovenia
austria Ireland austria Sweden
austria Israel austria Switzerland
austria Latvia austria United Kingdom



Member Assay Offices Of IAAO (International Association Of Assay Offices) By Country