limestone

The president defended his controversial decision to turn the manicured garden into a big stone patio on Saturday, while sharing a video of a construction worker damaging the limestone.

It would eventually lead to a refrigerated vault 200 feet below ground in a former limestone mine in rural Pennsylvania.

Then, earlier this summer, that lawn was replaced with limestone pavers.

We brought flashlights to hunt for fossils in the limestone beds, though mostly we just wandered.

It’s the most abstract of the bunch, inspired by “liquid deposits in limestone caves,” something I’ve never encountered and likely never will.