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 Canadian dollar $10 denominations, though sovereigns, to British standards, were issued in small quantities for some years. The minting of gold coins for circulation ceased due to the onset of the first world war, when the government of Canada recovered the majority of circulating gold coins to finance the war. Reissue plans were dropped in 1928. According to the Mint, a large quantity of the 1912–1914 gold coins were stored by the Bank of Canada for over 75 years. In 2012, the Mint offered 30,000 coins from the collection for sale to the public through its retail channels and stated that it