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 pound sterling Coins of the pound sterling The standard circulating coinage of the United Kingdom is denominated in pounds sterling (symbol "£"), and, since the introduction of the two-pound coin in 1994 (to celebrate the 300th anniversary of the Bank of England 1694–1994), ranges in value from one penny to two pounds. Since decimalisation, on 15 February 1971, the pound has been divided into 100 (new) pence. From the 16th century until decimalisation, the pound was divided into 20 shillings, each of 12 (old) pence. British coins are minted by the Royal Mint in Llantrisant, Wales. The Royal Mint also commissions the