It is dark in a way that daylight has never been.

It is quiet in a way that the living world is not.

The things that grow underground — the crystalline gypsum formations, the mirabilite flowers — are not like anything that grows in the forest or the river.

The ancient miners were not working in a neutral industrial space.

They were working in a place that was already understood as exceptional.

What Gypsum Could Do — And What Remains Unknown

The minerals that the ancient miners of Mammoth Cave spent centuries collecting were, outside the cave, essentially temporary.