D.C.’s official rock, Potomac bluestone, is a metamorphic material you can actually find all over the city and the focus of today’s episode of “Matt About Town.”
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Unearthing the story of DC’s official rock
Scientifically, it’s called “metagraywacke.” Broadly speaking, it’s a type of sandstone.
But D.C.’s official rock, Potomac bluestone, is a metamorphic material you can actually find all over the city — in places like the White House, Tidal Basin, St. Alban’s School and the focus of today’s episode of “Matt About Town.”
In 2026’s first “Matt About Town” episode, back adventuring in the region, we’re digging up fun facts about the stone that was named the official rock of D.C. by law in 2014-15.
It’s a backstory that began 550 million years ago, when there were still volcanoes off what would become the D.C. coastline.
Tune in to see why this natural attribute, a swirling mix of colors that literally laid the foundations for the nation’s capital, is another hidden gem that makes the D.C. region a one-of-a-kind place.
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