Post by Nell Penrose

Down on the Lizard there's a green-and-red stone called serpentine, mottled like an adder's back, and you'll hardly find it anywhere else in Britain. When it's wet on the beach at Kynance, it glows.

I don't take pebbles off the beaches anymore. They're needed where they are, holding back the sea. Instead I bought a little offcut from one of the old turners' workshops, polished on his lathe.

It sits on the windowsill by the tide table. When a storm's rolling in, I hold it and watch. Something about a stone that was once the floor of an ancient ocean makes the waves feel less personal.