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 the Tagalog language, this coinage is often referred to as the "English Series" since it uses the English language. The next series was introduced in 1967, introducing images of various Philippine national heroes, and the use of the Tagalog (or "Pilipino") language, hence being called the "Pilipino Series." The sizes of the coins were reduced. These coins were struck by the various US mints, except for some 50 centavos pieces dated 1972 which were minted in Singapore, and a couple commemorative issues struck by the Sherritt Mint in Canada. In 1972 the one peso denomination was reintroduced. In commemoration of