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 South African rand 20 and 50 cent coins were slightly redesigned by enlarging the numerals of the coin's denomination. From 2000 coins carried South Africa's new coat of arms. From 2002, R1, R2 and R5 coins carried the country's name in two of the official languages. Minting of 1c and 2c coins ceased at the end of March 2002. Minting of the 5c coin ceased on 1 April 2012, and the 10c coin, previously minted in bronze-plated steel, has since then been minted in copper-plated steel. The 5c coins are still legal tender, but have more or less disappeared from circulation, and most