I’ve been searching the beach for interesting stones for a few months now, and I’m surprised that the glass pebble pictured in today’s contact sheet is the first I’ve come across. You used to be able to find these quite often, not only clear glass, but amber and green too, sometimes even blue. I suppose that since we now use so much plastic for bottles, the dwindling of this man-made shoreline phenomenon is inevitable though, given the number of bars and clubs along the sea front, this still surprises me.

I remember the last big open air Fatboy Slim gig on the shore, the one when the beach was so packed with people they themselves seemed like pebbles. And indeed, because no one had considered what would happen if you held an event on the beach that started at low tide, a quarter of a million party people moved like pebbles too, driven up the beach by the rising waters as the evening drew on.

I also remember that the next morning the beach was so strewn with broken bottles it glittered, bejewelled, as if some profligate sultan had abandoned all his riches to the sea. It took a long time before the beach was safe to walk on barefoot and many of the splinters, rather than being collected during the clean up operation, would have settled below the stones where they probably still are, some by now ground down to sand but maybe not all. Now I think about it, I’m even more surprised this is the first piece of glass I’ve found. Perhaps it’s a fragment of vodka bottle whose contents were downed on that infamous night?

But leaving aside these memories, only now surfacing as I write, finding this one has made me ponder further. It’s glass, and it’s definitely a pebble, because it’s been worn smooth and rounded through the continual grinding of the waves on the shore. That’s what pebbles are aren’t they – things rounded smooth by the sea? But it isn’t a stone is it? Stones are formed purely as a result of geological processes. And this is why I’m not photographing it in the usual manner like the others I’ve found, because it isn’t a stone, is it? But now I’m wondering, if the definition of pebble is something worn smooth by the action of the sea, can you have wooden pebbles? Plastic ones? Larger pieces of seashell seem to qualify if rounded enough, as do the occasional fragments of brick or concrete.

This is now really bothering me.