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 Hawaiian dollar the Kingdom's motto. Many of these coins were subsequently destroyed or distributed among the friends of the king. These coins were minted in 1883-84 (all bearing the earlier date) at the San Francisco Mint, to American coinage standards and saw wide circulation on the islands. They were designed by Chief Engraver Charles E. Barber. Following American annexation in 1898 large numbers were withdrawn from circulation and melted. "trials" "official version" Mintages of the Hawaiian coins, and the numbers melted by the United States government following their demonetization in 1903, are as follows: In addition, 26 proof sets were made for