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 One Peso commemorative had reported mintages of 10,000 pieces. They weigh 20 grams, and are 90% silver. After the granting of independence to the Philippines in 1946, no coins were minted for the Philippine Republic until 1958, other than a small silver commemorative issue in 1947 to honor General Douglas MacArthur. Totals of 200,000 50 centavos and 100,000 one peso coins were minted with the general's image on the obverse and the national coat-of-arms on the reverse. Struck at the San Francisco Mint, they carry the "S" mintmark below the date. In 1958, the 20 centavos was replaced with a