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 1989, 1994, 1995 and 1996. Commemorative £2 coins have been regularly issued since 1999, alongside the standard-issue bi-metallic coins which were introduced in 1997. One or two designs have been minted each year, with the exception of none in 2000, and four regional 2002 issues marking the 2002 Commonwealth Games in Manchester. As well as a distinct reverse design, these coins have an edge inscription relevant to the subject. The anniversary themes are continued until at least 2009, with two designs announced. For a complete list, see Two pounds (British decimal coin). Outside the United Kingdom, the British Crown Dependencies