The Precious Metal at the Tip of the Washington Monument
In 1884, the peak of the Washington Monument was capped with a 100-ounce pyramid of pure aluminum. At the time, separating aluminum from its ore was so extraordinarily complex that the metal was rarer and more valuable than silver. Napoleon III reportedly reserved aluminum cutlery for his most esteemed banquet guests. Just two years later, in 1886, the Hall-Héroult smelting process was invented, causing aluminum production to soar and its price to plummet.
A Pyramid on Display at Tiffany's
In late 1884, as construction on the Washington Monument neared its final stage, an unusual artifact went on public display at Tiffany & Co. in New York City. Visitors could step across the floor and admire a small, gleaming pyramid measuring just under nine inches tall and weighing precisely one hundred ounces. It was not carved from marble, nor cast from solid silver or gold. Instead, it was crafted from pure aluminum by the Philadelphia metallurgist William Frishmuth. At the time, it was the largest single piece of aluminum ever cast, and its exhibition in a luxury jewelry showroom reflected just how extraordinary the metal was considered to be.
When the pyramid was hoisted to the top of the 555-foot obelisk in December 1884 and set into place as the monument's capstone, it served two distinct functions. Practically, it was designed to act as the terminal point of the structure's lightning protection system, capable of conducting electrical strikes harmlessly to ground rods. Symbolically, however, it was a bold statement of national technological ambition. Crowning the world's tallest masonry structure with aluminum was equivalent to capping it with the most sophisticated and expensive product that nineteenth-century chemical engineering could produce.
The Paradox of an Invisible Element
The extraordinary status of aluminum in the nineteenth century presents an apparent paradox: aluminum is the most abundant metallic element in the Earth's crust and the third most abundant element overall, surpassed only by oxygen and silicon. Vast deposits of aluminum compounds exist everywhere in soil, clay, and rock. Yet while humanity had mined, refined, and worked with copper, bronze, iron, and gold for thousands of years, pure elemental aluminum remained entirely unknown until the nineteenth century.