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 Rhodesian pound Commonwealth and the United Nations, as the Unilateral Declaration of Independence (UDI) was not recognized as legitimate. In 1966, the 'rebel' Rhodesian Government decided to issue a set of gold coins to commemorate the first anniversary of the UDI. These consisted of three denominations: - ten shillings (bearing a sable antelope on the reverse) (click for reverse image); - one pound - 5000 minted (bearing the "lion and tusk" armorial crest of Rhodesia on the reverse) (click for obverse image) (click for reverse image); and - five pounds - 3000 minted (bearing the arms of Rhodesia on the reverse) (click