Assying and Hallmarking

Assaying & Hallmarking dates back to antiquity and as such a number of countries have, besides the members of Vienna Convention 1972, adopted/passed the required legislation/rules/regulations to give it all the legal and valid requirements to make it more valuable and worth-full for their nations and nationals. Likewise, Pakistan being an independent and above all among the largest consumers of gold, has also taken steps to regulate and monitor the activities of gold sector. It was not only to address the stakeholders but also, at the same time, to bring laurels for the country in the international markets.

Introduction of Hallmarking is among the major initiatives of PGJDC. Assaying is the process of inspecting articles of gold/silver/platinum jewellery with respect to alloy composition and Hallmarking is the application of a series of marks onto precious metal jewellery which shows that the jewellery has been tested at an official Assay Office and found to conform to one of the accepted standards of fineness. The main objective of hallmarking is to facilitate trade while maintaining fair trade and consumer protection.

The Assaying and Hallmarking centers being established by PGJDC will provide the facility to accurately determine and officially record the proportionate contents of precious metals in jewellery. Official marks are used in many countries as a guarantee of purity or fineness of gold jewellery. For peace of mind and security to people’s investment in gold, it is imperative that the consumers understand the Hallmarking initiative taken by PGJDC. The Hallmarking Centers will play a pivotal role in inculcating the importance of Assaying and Hallmarking into the norms of Pakistani jewellery sector. Assaying and Hallmarking Centers will provide a paradigm and direction for the independent Assay Centers.

Assaying and Hallmarking Services

The following services are provided to cater to needs of the Gems & Jewellery sector,

  • Precious Metal Testing (Gold, Silver, Platinum, Palladium, etc) and
  • Hallmarking of Precious Metals

Assaying is carried out by a number of techniques which normally includes touchstone method, XRF Technique and Cupellation (Fire Assaying) describes as below:

  1. Touchstone testingis an ancient method for measuring gold content whereby a rubbing of the item is made on a special touchstone alongside rubbings of known reference samples and treated with nitric acid and a mixture of hydrochloric and nitric acids (Aqua Regia). The color change and rate of dissolution of the reacted area is compared to that of the reference sample. The touchstone method is particularly suited for testing of very valuable pieces, for which sampling by destructive means, such as scraping, cutting or drilling is unacceptable.
  2. X-Ray Fluorescence (XRF)is a non-destructive technique that is suitable for normal assaying requirements such as in-house quality control in manufacturing or for certifying gold content in retail outlets. It has accuracy of 2 – 5 parts per thousand under good conditions i.e. where the surface of the jewellery being measured is relatively flat and sufficiently large. It is a quick technique, an assay taking about minutes, and the computer can automatically print out the results. It also measures the content of other alloying metals present in the article. The XRF instruments measure the intensity of the generated gold X-ray by wavelength dispersion analysis.
  3. Cupellation (Fire Assaying)involves taking a small sample from the article, typically about 250 milligrams, weighing it accurately, wrapping it in lead foil with some added silver, cupelling it in a furnace at about 11000C to remove all base metals and then placing the resulting gold/silver alloy bullion in nitric acid to dissolve out the silver and re-weighing the resulting pure gold. This is the standard reference technique used by the National Assay Laboratories worldwide for Assaying and is covered in the International Standard, ISO 11426:1993.After having determined the purity of the article/bullion as per abovementioned assaying techniques, the mark is struck by laser marking machine to mark the article(s) of the found purity. Hallmarking is performed through a Laser marking Machine.
  4. Laser markingworks by using high power lasers to evaporate material from the metal surface. Two methods exist, 2D and 3D laser marking. 2D laser marking burns the outline of the hallmarks into the object, while 3D laser marking better simulates the marks made by punching.

A Hallmarked jewellery article will be principally marked by the Hallmarking Centers being established by PGJDC. These centers will provide third party assurance. Hallmarking Centers, being not involved in jewellery trade of any sort, will work as an independent third party. This third party effect will help in assuring impartial marking of the jewellery article. It is a fact that, hallmarked jewellery articles are trusted and recommended worldwide. Thus, with standardization as such, it is expected to boost direct exports and can enhance the business generated in international gems and jewellery trade shows

PGJDC’s Assaying and Hallmarking Centres
Introduction of Assaying & Hallmarking in Pakistan is among the major initiatives undertaken by PGJDC for introducing quality standards into the local industry and increasing the credibility of Pakistani products in international markets.

The Assaying and Hallmarking centres being established by PGJDC at Karachi and Lahore play a pivotal role in inculcating the importance of Assaying and Hallmarking into the norms of Pakistani jewellery sector. At these state-of-the-art Centres, precious metal article testing is done for the Gems and Jewellery Sector on latest Machinery and Equipment as per international standards. The details of these centres are as under:
a.      Assaying and Hallmarking Centre Lahore:

Contact Person:     Mr. Khalid Mehmood
Incharge

Assaying & Hallmarking Centre – Lahore
3rd Floor Rana Center, 18 Jamal ud Din Afghani Road, (Near AG Office) Lahore
Tel: 042-37245334, 042-37245335,
E-mail:
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b.      Assaying and Hallmarking Centre Karachi:

Contact Person:     Mr. Shakaib Hayder
Assistant Manager Accounts and Admin

Assaying & Hallmarking Centre – Karachi
2nd Floor, Pakistan Handicraft Chambers, 251 R.A Lines, Abdullah Haroon Road, Saddar, Karachi
Tel: 021-35220294-5, 021-35651346-7
E-mail:
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