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.
Trial of the Pyx for every ten pounds of silver minted. A trial was normally conducted every three months. The presiding judge is the Queen's Remembrancer (or King's Remembrancer when the sitting monarch is male), the Senior Master of the Queen's Bench. It is his or her responsibility to ensure that the trial be held in accordance with the law and to deliver the jury's final verdict to Her Majesty's Treasury. Where and when a trial is to take place is at the Treasury's discretion, though there must be a trial in any year during which the Royal Mint issues coins. Coins to be