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 Philippine peso 5 Piso denomination was stopped, but resumed (in a new smaller size) concurrent to the final four years of the Flora and Fauna Series which featured reduced sizes for all denominations. The Flora and Fauna Series was struck from 1983 through 1994. In 1995 the New BSP Series was introduced, which is still circulating today, but might be demonetized soon. Only this current series of coins are legal tender as of January 2, 1998, when the Bangko Sentral ng Pilipinas issued BSP Circular No. 81 which called for the demonetization of all previous existing Central Bank coins minted before 1995.