An initially precious metal that became common is aluminum. While aluminum is the third most abundant element and most abundant metal in the Earth’s crust, it was at first found to be exceedingly difficult to extract the metal from its various non-metallic ores. The great expense of refining the metal made the small available quantity of pure aluminum more valuable than gold. Bars of aluminum were exhibited at the Exposition Universelle of 1855, and Napoleon III’s most important guests were given aluminum cutlery, while those less worthy dined with mere silver. In 1884, the pyramidal capstone of the Washington Monument was cast of 100 ounces of pure aluminum. By that time, aluminum was as expensive as silver. The statue of Anteros atop the Shaftesbury Memorial Fountain (1885–1893) in London’s Piccadilly Circus is also of cast aluminum. Over time, however, the price of the metal has dropped. The dawn of commercial electric generation in 1882 and the invention of the Hall–Héroult process in 1886 caused the price of aluminum to drop substantially over a short period of time. Silver coins are possibly the oldest mass-produced form of coinage. Silver has been used as a coinage metal since the times of the Greeks; their silver drachmas were popular trade coins. The ancient Persians used silver coins between 612-330 BC. Before 1797, British pennies were made of silver.
As with all collectible coins, many factors determine the value of a silver coin, such as its rarity, demand, condition, and the number originally minted. Ancient silver coins coveted by collectors of Rare Metal Blog include the Denarius and Miliarense, while more recent collectible silver coins include the Morgan Dollar and the Spanish Milled Dollar.
Other than collector’s silver coins, silver bullion coins are popular among people who desire a “hedge” against currency inflation or store of value. Silver has an international currency symbol of XAG under ISO 4217.