Seep

In the FossilForge courtyard, a small spotted newt set a jar of cloudy water on the bench and, beside it, a twig — one end ordinary brown wood, the other grey and heavy and cold, stone in the exact shape of wood, down to the ridges of bark. The kids passed it hand to hand, frowning. "It's the same twig," said Seep, who talked at the speed of dripping water. "One end is still wood. The other has sat in my spring a long, long time. The water carries stone in it — dissolved, too small to see, like sugar in tea. Bit by bit it seeps into every tiny pore in the wood and settles. Fill every space and you're left with wood-shaped stone. The wood is mostly gone. The shape stayed." A girl held it to the light. "So it turned to stone without falling apart first." "That's the whole trick," said Seep. "Kept, before it could vanish."

Seep learned to see it in the dripstone caves where she grew up, by a limestone cave mouth where water so full of dissolved stone built things drip by patient drip — stone icicles from the ceiling, slow mounds from the floor. A small newt, she once dropped a favourite acorn into a shallow cave pool and forgot it; years later she found it perfect in every ridge and heavy as a pebble. She remembered the tender, enormous feeling of it — that slow, unhurried water had reached into a small soft thing and kept it, long after it should have rotted into the mud. Lasting, she understood, was not something a thing did on its own. It was rare, and lucky, and gently done to it.

At the academy she taught the whole recipe, because she thought it only fair the children knew how rare a fossil is — and its proper name. "This is taphonomy — everything that happens between death and discovery. Step one, almost always: a creature dies and is eaten, decays, or washes away, and nothing is left." She swept most of her carved tokens — a leaf, a fish, a shell — gently off the bench. "That is the fate of nearly everything that has ever lived. But now and then, a very few are buried fast — under mud, sand, or volcanic ash — before scavengers and rot can finish. Rapid burial is the first narrow escape." She left one token and dribbled cloudy water over it. "Then comes permineralization: groundwater carrying dissolved minerals soaks down into every pore of the buried thing and deposits stone, grain by grain, for ages. The soft parts go; the mineral stays in their shape." She set the grey twig beside it. "When the ground finally erodes away above it, someone finds a fish, a leaf, a shell — made of stone. And notice: this is a chain of independent unlikely steps — escape decay, get buried fast, sit undisturbed while water works, then be exposed by erosion at the exact time a person is looking. Multiply small chances together and the total is tiny. That's why fossils are rare — not one hard step, but many, each of which usually fails."