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 copper-nickel. 1 sen coins were effectively worthless, and only a token number of 100,000 were minted, all dated 1952. 5 sen coins were more useful and were also minted dated 1954, as was the 10 sen. From 1954, Indonesia began to eliminate use of Malay Arabic script (Jawi), which had been a feature of the coins of the Netherlands Indies as well as of past Islamic sultanates in the archipelago. The 50 sen coin was the first to be changed, with the Arabic text simply removed from the coin for its 1954-dated minting. The 25 sen was the next to