Stone that used to be a forest.

The short version

A tree fell. Then chemistry took over.

At the end of the Cretaceous, the ground where Parker now sits was a warm, wet lowland at the foot of a rising mountain range. Rivers ran east off the young Rockies carrying sand, gravel and volcanic ash. Trees fell into that mess and were buried fast — fast enough that the usual rot never got started.

Groundwater moving through all that ash was loaded with dissolved silica. Over thousands of years it seeped into the waterlogged wood and crystallized inside it, filling cell walls and hollow vessels one at a time. The wood did not so much turn to stone as get replaced by it, copy for copy, at the scale of individual cells.

Iron, manganese and other trace metals came along for the ride. They are the reason a piece from one hillside comes out blood red and one from the next ridge comes out honey, grey or near black.

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