Annex H also shows how to derive London gross
troy ounce weights rounded to the nearest 0.1 or 0.025 troy ounces for silver
and gold respectively. Please click here to download an Excel
spreadsheet including the same calculations.
This edition of the rules was published in December 2013. Click on the link below for details of changes made to the rules since 1934.
Bona fide refiners who are in the final stages of preparing to apply for LBMA Good Delivery accreditation may purchase gold and/or silver self-testing samples from the LBMA. The samples can be used for a final check of the laboratory's assaying accuracy before the refiner submits its application for accreditation.
A set of self-testing samples is limited to a maximum of 6 per refiner, for each metal, and the cost of supplying these is as follows:
(a)Approximately 10-gram gold samples at £465 per sample, or a total of £2,790 for a set of 6, including the value of the metal content, plus VAT (as applicable) (b)Approximately 30-gram silver samples at £415 per sample, or a total of £2,490 for a set of 6, including the value of the metal content, plus VAT (as applicable)
The cost of shipment of the samples to the refinery will be payable in addition.
Please note that, self-testing assay results (in fineness terms to 2 decimal places) must be submitted to the LBMA within 6 weeks of the laboratory confirming receipt of the samples. For each sample, the laboratory should supply: •The number of trials carried out •The average fineness and •The standard deviation achieved.
On receiving these results, the LBMA will then provide the refiner with the reference assay values (expressed in fineness to 2 decimal places) for the samples. The LBMA will keep the submitted results confidential. In other words, they will not be provided either to the Physical Committee or to the LBMA's Referees group, except on an anonymous basis which would not allow the refiner to be identified. Failure of the refiner to submit its assay results within 6 weeks could result in the subsequent application being rejected.
For questions and further information regarding the work of the LBMA in relation to Good Delivery please contact Jyoti Amin, Good Delivery List Officer.