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 guides you through 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)?

An Assaying and Hallmarking Centre (AHC) is a private facility which is recognised, licensed and monitored by the Bureau of Indian Standards (BIS) for testing the purity of gold and for applying the official hallmark. There are more than 1,400 recognised centres in BIS hallmarking ecosystem across India. The hallmarking scheme is intended to protect consumers from adulteration and to ensure that manufacturers and sellers of articles of precious metals adhere to the declared purity standards.

Recognised AHCs operate under BIS requirements, so a hallmark applied at one centre carries the regulatory significance of a hallmark applied at another recognised centre.

Which Gold Items Must Go Through a Hallmark Testing Lab?

Mandatory hallmarking applies to specified categories of gold jewellery and gold artefacts sold in India in accordance with applicable government notifications and BIS requirements. BIS recognises various fineness grades for hallmarking purposes, including:

• 14 carat (585 fineness)
• 18 carat (750 fineness)
• 20 carat (833 fineness)
• 22 carat (916 fineness)
• 23 carat (958 fineness)
• 24 carat and higher-purity categories such as 995 fineness and above

The categories subject to mandatory hallmarking, exemptions and operational requirements may vary based on prevailing regulations and amendments issued from time to time.

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. 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 typically used for most submissions because it offers a fast and non-destructive method of assessing metal composition. Since the process does not damage the article, it is commonly used for routine hallmarking assessments.

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 most 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.

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 can be carried out through the BIS Care App, available on Android and iOS platforms.

The process generally involves:

1. Opening the BIS Care App.
2. Selecting the "Verify HUID" option.
3. Entering the HUID displayed on the jewellery article.

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:

• Recognition number
• Centre location
• Contact information
• Recognition validity details

Filtering options are available by state, district and region, making it easier to identify nearby centres.

Before visiting a centre, it may be useful to confirm:

• Whether walk-in submissions are accepted
• Whether both gold and silver articles are handled
• Current processing timelines
• Applicable fees

According to BIS communications, hallmarking charges have been notified at approximately ₹45 per 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 the 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 will undertake in valuing pledged gold, but the final decision on valuation is at the lender’s discretion and they will undertake their own testing and assessment procedures.

However, the official BIS portal is the primary source for the latest information. Charges and operational procedures may be revised from time to time as per the requirements of hallmarking.

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