The many marbles of the Washington Monument
From afar, the Washington Monument seems like a relatively simple, straightforward piece of construction. A tall, stone pillar of a seemingly monochrome tint, it stands upright in the center of the capital, culminating in a sharp, needle-like point stretching toward the sky.
But get a little closer, and you realize it's a little more complex than it may at first seem.
Texas, Sheffield or Cockeysville?
Those with a keen eye – or a familiarity with masonry – will notice that the tribute to the first president of the United States is actually a few different shades of white. This is owing to two distinct phases of construction, which necessitated the use of two different kinds of marble.
The first 152 feet are made from Texas marble, a coarse-grained, white and almost purely calcium carbonate variety. This isn't the Texas you're familiar with though – it was actually a village just north of Baltimore. Construction proceeded between 1848 and 1854, but politics and a lack of money led to a decades-long hiatus.
The monument's construction was next taken up in 1879, at which point marble from Sheffield, Massachusetts was sourced, in order to fit with the shade of marble used until then. Unfortunately, issues with the delivery and quality of the marble led builders to abandon this variety only a year in, leading to the third and final marble type to be chosen for the remaining 400 or so feet: Cockeysville marble, from Maryland. It finally opened in 1888, standing at an impressive 555 feet tall.
Weather effects create color change
The Cockeysville marble contains large amounts of magnesium, giving it a pale gray tint, so it never quite matched up with the other marbles used. However, the stones resembled each other enough to not be noticeable. But over time, the effects of rain and wind have weathered the different marbles differently, leading to a clear distinction in color.
That's why it's important to seal your stone, preventing this state of affairs from occurring by protecting it from weather damage. Use Dry-Treat's STAIN-PROOF Original™ to keep water, oil and other substances out of your stone.