Precious metal status

An interesting case of a once-precious metal that is now common is that of aluminium. Although aluminum is one of the most commonly occurring elements on Earth, it was initially found to be exceedingly difficult to extract from its various ores. This made aluminum more valuable than gold. Bars of aluminum were exhibited alongside the French crown jewels at the Exposition Universelle of 1855, and Napoleon III was said to have reserved a set of aluminum dinner plates for his most honored guests. Additionally, the pyramidal top to the Washington Monument is made of pure aluminum. At the time of the monument's construction, aluminum was more expensive than silver, gold, or platinum. Over time, however, the price of the metal has dropped; the invention of the Hall-Héroult process in 1886 caused the high price of aluminum to permanently collapse.