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 coins minted in 1911 with a mintage of 209,972. The Canadian Coin News publication printed an article showing a well-worn 1911 50¢ example that did have the "DEI GRA" abbreviation. This coin has not yet been certified as genuine, having been rejected by ICCS, the popular Canadian grading company. The 1911 pattern dollar coin was produced with the 'DEI GRA' abbreviation on the two known silver examples and the one known example in lead. In 1920, the fineness of the silver coins was changed from .925 fine silver to .800 fine silver, and the size of the cent was reduced.