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 Indian rupee when the Unity in diversity series was launched. Cupro-Nickel coins are not minted anymore. Ferritic Stainless Steel coins of Two and Five Rupee denominations are currently in production. In 2004, RBI issued a series in denominations of 1 rupee, followed by 2 rupee and 10 rupee in 2005. These issues however came into circulation in 2006, and created a controversy over their design. 10 rupee coins were the first bimetallic coins issued in India, and because of the controversy and being minted in only one mint, most of the coinage never found its way into circulation. The ones which did