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 not yet available on the number of mintage. A press release from Reserve Bank of India mentioned that there will be two themes of 10 rupee coins: "Unity in Diversity" and "Connectivity and Information technology". From 2008 coins based on the second theme, "Connectivity and Information technology", were also released. The coin depicts 15 rays above the numeric 10. It was again minted only by the Noida mint and was not easily available in circulation. From 2011, the same theme was continued with a slight design change showing 10 rays instead of the earlier 15 and the introduction of the