Metallurgical assay and the U.S. Mint continue to produce precious metal bullion coins for collectors and investors. The precious metal purity and content of these coins is guaranteed by the respective mint or government, and, therefore, the assay of the raw materials and finished coins is an important quality control. In the UK, the Trial of the Pyx is a ceremonial procedure for ensuring that newly minted coins conform to required standards. Metallurgical assay A metallurgical assay is a compositional analysis of an ore, metal, or alloy. Some assay methods are suitable for raw materials; others are more appropriate for finished goods.
William the Conqueror increased to as much as six shillings per hide. Coinage between the various parts of his domains continued to be minted in different cycles and styles. English coins were generally of high silver content, with high artistic standards, and were required to be re-minted every three years. Norman coins had a much lower silver content, were often of poor artistic quality, and were rarely re-minted. Also, in England, no other coinage was allowed, while on the continent other coinage was considered legal tender. Nor is there evidence that many English pennies were circulating in Normandy, which shows little attempt to