bullion products (1kg gold bar, 10oz gold bar and 100oz silver bar) legally Allocated and Operationally Segregated storage is available through the use of an electronic Vault Warrant, which allocates a unique bar serial number. Approved refiner list Source Country Refinery Location Metal Hubs Argor-Heraeus SA Switzerland Mendrisio AU, AG, PT All Hubs Heraeus Ltd Hong Heraeus Precious Metals GmbH amp;. Total weight as stamped on each Bar. A ledger to ledger inter-bank contract transaction Bank Officer to Bank Officer. The vault holdings report and the Inspectorate audit report will be reviewed to ensure that everything is in order. Physical precious metals are one of the very few standardised asset markets that has not gone electronic in the institutional environment. The Buyer and the Seller agree on a window time for exchange. The exchange is able to arrange for bullion to be withdrawn from the exchanges Vault Network and delivered to an approved location of the owners choosing. Certificate of Origin.