Analysis process
Back to Assaying
Phase 1 - The laboratory shall clean and drill the samples, putting the drillings from each sample into separate envelopes. The laboratory shall then analyze each individual sample to verify the homogeneity of the melt. If homogeneity is verified and there is an agreement for exchange of assays between the Client and Valcambi, three equal final samples of usually 5 grams each shall be prepared with the drillings of the sample taken from the melt just before pouring. If homogeneity cannot be proved the lot shall be re-melted.
Phase 2 - The obtained samples are sealed by the Representative, labelled with the melt number and distributed as follows:
a) One sealed sample is kept with Valcambi at the Client’s disposal or delivered to its Representative, if present. Valcambi will mail such sample to the Client or Client’s requested laboratory upon written instructions;
b) One sealed sample is kept at Valcambi’s laboratory to perform the analysis;
c) One sealed sample remains with Valcambi for contingent Umpire assay.
Phase 3 - Sampling of the recovery bar: the laboratory shall sample the recovery bar. The samples taken shall be put into separate envelopes, labelled with the melt number and the drilling side. The sample shall be analyzed by Valcambi to verify the homogeneity of the recovery bar.
Phase 4 - Preparation/sealing of the final samples of the recovery bar: if homogeneity of the recovery bar has been proved, three sealed envelopes shall be prepared, containing each usually 5 grams of drilled material, after having mixed equal parts of the drillings taken from the recovery bar.The samples obtained from the recovery bar are sequentially stored with the other samples.
Phase 5 - Assays: the assays shall be carried out by the fire assay method. Results of such assays shall be exchanged simultaneously between Client and Valcambi by mail, on a date to be agreed upon and followed by fax or e-mail the following day. Should the difference between the exchanged results not exceed the Splitting Limits, then the arithmetic mean of the results of Valcambi and Client shall be taken as final.
Phase 6 - Splitting Limits: subject to exchange of assays being contractually agreed upon the splitting limits are usually: 0.05% for Au and 0.20% for Ag in case of gold base material; 0.03% for Au and 0.20% for Ag in case of silver base material. For Pt and Pd Valcambi's assays will be final and binding.
Assay results shall be expressed to four (4) significant figures for 995,0 and higher fineness and five (5) significant figures for gold below 995,0 fineness.
Phase 7 - Umpire
a) If the difference between the assays exceeds the splitting limits, both Client and Valcambi shall have the right to ask for assays to be remade or to request an umpire analysis.
b) The second assay or the Umpire analysis, if requested, has to be initiated within 4 (four) Business Days after the request is made.
c) The Umpire assayer shall not be the Representative of Client or Valcambi.
d) The Umpire assayer shall be one of the firms previously agreed upon on a rotational basis and shall use the fire assay method. Any other organisation may be designated as Umpire assayer by Client and Valcambi from time to time upon mutual agreement.
ALS Inspection (Formerly Stewart Group Inspection and Analysis)
Caddick Road
Knowsley Business Park
Prescot L34 9HP
United Kingdom
Alex Stewart International
20 Sefton Business Park
Aintree, Liverpool
Merseyside, L30 1RD
United Kingdom
Inspectorate International Limited
2 Perry Road
Witham
Essex CM8 3TU
United Kingdom
Federal Customs Administration
Central office for precious metals control
Industriestrasse 37
2555 Brügg
Switzerland
SGS S.A.
1 Place des Alpes
1211 Geneva
Switzerland
e) Umpire results
I. If the difference between Valcambi's and the Client's assay results is equal or less than
0.05% for Au and 0.20% for Ag in case of Gold Base Material
0.03% for Au and 0.20% for Ag in case of Silver Base Material
the average of the assay results of the Client and Valcambi shall be taken as the agreed Settlement assay;
II. If the subsequent Exchange exceeds the splitting limits, the Umpire sample shall be submitted within 4 (four) business days to one of the assayers set forth under (d) above which shall act as Umpire assayers on a shipment by shipment rotation basis.
III. If Client or Valcambi submit the Umpire sample to an Umpire assayer and the Umpire's assay results are between the re-assay results of Client and Valcambi, the Umpire's results shall be final and binding on both parties for settlement.
IV. If the Umpire's assay results are outside of the re-assay results of Client and Valcambi, the assay results of the party closest to the Umpire re-assay results shall be final and binding on both parties for settlement.
f) The cost of the Umpire’s assay shall be borne by the party whose re-assay results are furthest from that of the Umpire. if the Umpire's assay should be the arithmetic mean between the re-assay results of the two parties, the costs of the Umpire's assay shall be born equally by Client and Valcambi.