Ensuring Excellence: How LBMA Referees Uphold Gold and Silver Standards
Thu May 08 2025
As two new Referees are selected to join LBMA’s Referees panel, the Alchemist explores how their work upholds the quality of the physical bars which underpin trust in the precious metals industry.
If the Good Delivery List lies at the heart of the London bullion market, then LBMA’s Referees are its heartbeat. The Referees act as the gatekeepers, upholding the highest standards in bullion production and certification.
LBMA was founded in 1987 to represent market participants and ensure quality refineries for the technical aspects of maintaining the Good Delivery List. In 2000, when Engelhard-Clal decided to close its Chessington refinery and lab, it began to make sense for LBMA to have more ownership of the technical accreditation process. And so, in 2001, LBMA invited all Good Delivery gold and silver Refiners, who were also LBMA Associates, to apply to become part of an expanded Referee’s panel. The new panel was announced in 2003.
Who are the Referees and what do they do?
In March this year, after a long and rigorous process, Agosi AG and Gold Corporation (T/A The Perth Mint) were selected to join the existing panel of Referees. The existing panel comprises Argor-Heraeus SA, Metalor Technologies SA, MKS PAMP SA, Rand Refinery (PTY) Ltd, and Tanaka Kikinzoku Kogyo.
LBMA Referees – now numbering seven – carry out assays and chemical analysis of gold and silver to the highest possible levels of consistency, precision and accuracy. They also manufacture gold and silver reference samples, which are free from detectable inhomogeneity and assayed to very high levels of accuracy.
The LBMA Referees have demonstrated standards of assaying that are significantly above those required for other Refiners on the Good Delivery List. Only in this way is it possible for them to manufacture the required reference samples and to test with sufficient reliability the samples provided by those being monitored.
Together, this group conducts the following essential activities:
The most important area of work from the Referees is the examination and testing of sample bars provided by refiners which are seeking Good Delivery accreditation. After satisfying LBMA about the accuracy of its assaying ability, an applicant must submit unmarked large bars. These bars must comply with LBMA’s Good Delivery criteria for both physical and chemical properties. After physical examination in a London vault, these bars are divided into two batches which are sent to two of the Referees for a more detailed examination and chemical analysis. The Referee and the applicant do not have any direct contact, and the Referees are never aware of the applicant’s name at any stage of the process. This ensures complete anonymity.
The examination, testing and reporting on these bars by the Referees follows a long-established procedure which is carried out in two stages. The first stage involves weighing, visual inspection and the assay of cut samples with the second stage involving the melting and dip sampling of two of the bars and a full elemental analysis.
The Referees cross-check assaying of the dip samples submitted by the GDL Refiners every three years as part of the PAM programme. These assaying and analytical reports provided by the Referees allow LBMA to decide whether the Refiner has passed the technical requirements of Proactive Monitoring. This allows LBMA to give useful feedback to the Refiner regarding the fine tuning of its assaying work.
Every year, the Referee working group decides the composition for the Proficiency Testing Scheme. This is discussed in great depth by the group and LBMA to ensure a challenging and exciting composition is available for the market to test each year. The manufacture and analysis of proficiency testing samples is prepared by the Referees panel.
Over the years we have seen good participation from both GDL and non-GDL laboratories and the number of labs achieving scores of < 2 is increasing, and general improvement can be seen on accuracy and precision.
The silver market has been extremely active during the past year and many silver refiners are keen to achieve LBMA Good Delivery accreditation. This means that there is an increasing demand for silver reference samples to test applicants. The Referees each agreed to manufacture up to five new sets of silver samples and this project is largely on the way to completion.
Members of the Referees working group have also been involved, together with other well-qualified GDL Refiners, in the development of Certified Reference Materials (CRMs). These materials are available to any laboratories wishing to calibrate their analytical equipment to LBMA standards. Since their initial manufacture in 2010, CRMs have become an essential component of Good Delivery best practice, promoting quality and good practice in the refining and trade of gold and silver.
Look out for the new gold and silver CRMs in 2026
Source: https://www.lbma.org.uk