I found this curious rock in the Brecon Beacons, a mountainous range in South Wales. The regular dotted pattern stood out from the plan slate and gravel in the area and I'm not sure if these are fossils or quartz?
The white dots run through the whole stone.
This particular rock was part of a gravel pathway and shallow quarry where the gravel was excavated from. This dotted pattern stone seemed quite abundant there.
The dark rock is fairly unremarkable and can be scratched with a coin. I believe there are quite a few slate quarries in the area and it does feel a bit like slate or similar.
I can't be certain it's the same but in the quarry it looked like the dots slightly extruded from some of the rocks (my apologies for the photo quality)
Does anyone know if this is fossil or quartz or how this pattern could of formed? I'm really curious.