How Hallmark Testing Labs Work: The Steps Before a BIS Stamp Is Applied to Jewellery

In India, every hallmarked gold jewellery article typically takes a standard journey. From a jeweller's tray to a licensed hallmark testing lab, through a purity test, and back, with a stamp that certifies what the metal contains. This guide traces that journey, step by step, through a BIS approved Assaying and Hallmarking Centre (AHC), the facility that tests gold and applies the official hallmark under the hallmarking framework of India. It covers what these labs are, which items may require hallmarking, the testing methods used, the components of the hallmark, verification through the BIS Care app, and what the process may mean during gold loan valuation.

What Is a Hallmark Testing Lab (Assaying and Hallmarking Centre)?

The Assaying and Hallmarking Centre (AHC) is an organization run on private basis and licensed, authorized and controlled by the Bureau of Indian Standards (BIS) for assaying the purity of gold and hallmarking. There are more than 1,400 registered Assaying and Hallmarking Centres in the network of the BIS for hallmarking, although the number fluctuates because recognitions are awarded and revoked. The hallmarking scheme is meant to prevent consumers from being cheated and to make sure that the manufacturers/sellers of articles made of precious metals stick to the stated standards of purity.

Recognized AHCs are subject to BIS requirements so a hallmark at any one center has the regulatory standing of a hallmark at another recognized center.

Which Gold Items Require Hallmarking Through a Testing Lab?

Certain types of gold jewellery and gold articles that are sold in India are mandatorily required to have hallmarks as per government notifications and BIS guidelines. The various types of fineness of gold for which hallmarking is defined by BIS are 14 carat (fineness 585), 18 carat (fineness 750), 20 carat (fineness 833), 22 carat (fineness 916), 23 carat (fineness 958) and 24 carats (and any higher fineness like 995).

The categories of mandatory hallmarking and the exceptions to them can vary from time to time as per regulations and amendments.

Step-by-Step: What Happens Inside a Hallmark Testing Lab

1. Submission

The jeweller, and in some instances an eligible applicant, submits the gold items along with details of the declared caratage. The lot is logged into the centre's system.

2. Registration

Each item is weighed, registered and assigned a record within the hallmarking workflow. Documentation generated at this stage supports traceability throughout the process.

3. Purity Testing

The primary testing method used by most centres is X-ray Fluorescence (XRF) testing. XRF enables rapid, non-destructive analysis of the metal composition.

Where results are borderline, disputed or require additional confirmation, the centre may use fire assay testing. This process involves analysing a small sample under laboratory conditions to determine gold content with a high degree of accuracy.

4. Standards Check

The measured purity is evaluated against the applicable BIS fineness requirement for the declared caratage. For example, an item submitted as 22-carat gold is expected to meet the 916 fineness standard.

5. HUID Generation

For each article that meets the required standards, a Hallmark Unique Identification (HUID) code is generated and recorded within the BIS system. The HUID serves as a permanent identifier linked to the hallmarked article. The HUID is a unique 6-digit alphanumeric code assigned to each hallmarked jewellery item.

6. Hallmarking and Return

After successful testing and registration, the hallmark is applied and the article is returned along with the relevant documentation generated through the process.

XRF Testing vs Fire Testing: Which Method Does the Lab Use?

XRF testing is normally conducted in most cases as it provides a quick and non-invasive means of checking the composition of the metals. This method being non-destructive, it is usually employed for regular hallmarked tests.

Fire assay testing is generally reserved for situations where additional confirmation is needed. Although it requires testing of a small sample, it is widely considered one of the more precise methods for determining gold purity.

The use of both testing approaches helps recognised hallmarking centres assess purity against the prescribed standards before applying a hallmark.

What the BIS Hallmark Stamp Contains: Understanding the Components

A BIS hallmark contains identifying information that may help establish the authenticity and purity of the article.

Note: The components shown are indicative of the current three-mark HUID system. Applicable marking requirements may vary with regulatory updates and prevailing BIS guidelines.

Since the introduction of HUID-based hallmarking, traceability relies primarily on the unique identification code assigned and recorded in the BIS system. Consumers may use this code for verification purposes.

How to Verify a Hallmark After Lab Testing: The BIS Care App

Verification may be done using the BIS Care App which can be accessed via Android and iOS platforms. Verification typically entails accessing the BIS Care App, tapping on the “Verify HUID” feature, and inputting the HUID found on the jewellery item.

Where a matching record exists, the app may display information such as the hallmarking details and declared purity associated with the HUID. Consumers may also visually confirm the presence of hallmark components, including the BIS mark, fineness mark and HUID.

Hallmark vs Purity Certificate: What the Lab Issues and Why It Matters for Gold Loans

The hallmark and a purity certificate serve different purposes.

The hallmark is a physical marking on the article indicating that it has undergone testing through the recognised hallmarking framework. A purity certificate, where issued, provides documentary information relating to the tested article, including details such as purity and weight.

In the context of a gold loan, hallmark information may assist in the lender's valuation process because it provides an independently verified purity reference. However, lenders generally conduct their own evaluation, testing and valuation procedures in accordance with applicable policies and regulatory requirements before determining eligibility, loan amount or other terms.

How to Find a BIS-Approved Hallmark Testing Lab Nearby

The official BIS portal available through Manak Online maintains a directory of recognised Assaying and Hallmarking Centres across India. Listings generally include the recognition number, centre location, contact information and recognition validity details. Filtering options are available by state, district and region, making it easier to identify nearby centres.

Details such as whether walk-in submissions are accepted, whether both gold and silver articles are handled, current processing timelines and applicable fees generally vary by centre and are available through the centre or the directory listing.

According to BIS communications, hallmarking charges have been notified at approximately Rs 45 per gold article, excluding applicable taxes, though charges may be revised from time to time. Many standard submissions may be processed within approximately 1-2 working days; however, actual turnaround times depend on the centre, workload and testing requirements.

Note: All figures are indicative. Actual fees, timelines, processes, eligibility requirements and applicable standards may vary depending on the recognised centre, regulatory updates and prevailing BIS guidelines.

Conclusion

The strength of a BIS hallmark lies in the system behind it: the recognised testing centres, the standard purity testing, the checks against the required fineness and the registration of a unique HUID before the hallmark is applied.

For consumers, hallmarking gives an added degree of confidence that the declared purity has been independently verified under the BIS system. A hallmarked article can assist in the valuation process that a lender undertakes when valuing pledged gold, but the final decision on valuation rests with the lender, which undertakes its own testing and assessment procedures in accordance with applicable policies and regulations.

The official BIS portal remains the primary source for the latest information, as charges and operational procedures may be revised from time to time under the hallmarking framework. Valuation procedures, disclosures, and collateral handling are carried out in accordance with applicable policies and regulations.

Disclaimer : The information in this blog is for general purposes only and may change without notice. It does not constitute legal, tax, or financial advice. Readers should seek professional guidance and make decisions at their own discretion. IIFL Finance is not liable for any reliance on this content. Read more