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.
Coins of the Philippine peso 25 centavos and all coins were resized to be the same diameter as their US equivalents, albeit in more base metals, other than the centavo. The same seated man with anvil and volcano or standing liberty with anvil and volcano designs were retained for the obverses while the seal of the Central Bank of the Philippines dominated the reverse. These coins were minted by the Philadelphia Mint from 1958 through 1963, and then by the Royal Mint in England and the Vereinigte Deutsche Metallweke in West Germany in 1965 (dated 1964) and 1966. In view of all subsequent issues using