My old fossil in a split stone

I like this old stone which we've had for a long time. There is a chance that it was one I discovered on a beach in Swansea many decades ago, but my memories of that long ago are hazy. That stone split in two with one of the faces containing a central object around which the sandstone had coalesced to form a fossil. This would appear to fulfil those criteria.

Today it has found its way onto the table on the patio. Rather late in the day a few rays of sunshine were highlighting small parts of it and the slats of the weathered table when I closed in for the photo.