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 rupiah Coins of the rupiah Indonesian rupiah coinage was first issued in 1951 and 1952, a year or so later than the first Indonesian rupiah banknotes printed following the peace treaty with The Netherlands, agreed in November 1949. Although revolutionary currency had been issued in by the provisional Republic of Indonesia between the declaration of independent on 17 August 1945 and 1949, it had all been formed of paper, metal being far too scarce for the internationally isolated government to use as currency. Due to high inflation in the late 1950s and early 1960s, no coins were minted after 1961, and