Galaxy diamond on a thigh

You left before the speeches, so you missed Mr Okafor admitting he never once read our Year Nine essays. I kept the paper cup he drank his squash from. The thing I actually meant to tell you is about the stone.

Remember the spoil heap behind the science block, where we dug for clay for the kiln and got told off for it? Last month the council cleared it for a car park, and a man from the site office handed me a carrier bag of what they'd turned up. Mostly broken brick and bottle glass. But at the bottom was a stone the size of a hazelnut, cut into facets, dark at the edges. When I held it up to the window the middle looked like the sky over the playing fields the summer we stayed out until the caretaker swept his torch across the grass.

The jeweller on Fore Street peered through his loupe for ages, then said it was old glass, a marble or a bit of a bottle, and the blue and pink swirl inside was just a flaw that caught the light. He offered me four pounds. I said no thank you and walked out feeling oddly pleased, the way you do when someone tells you the truth and it doesn't matter.

I went up to the field on Saturday with it in my coat pocket. The lights were off and the grass was wet. I held the stone to the sky and the speckles caught the last of the dusk, and I thought, well, somebody made this to look like that, and it still does. Write when you're back from Lisbon. I'll bring the stone, and you can tell me I'm daft.