Leopardskin Spherulitic Rhyolite

I'm not sure where the can be drawn between a thunderegg, thunderegg conglomerate and spherulitic rhyolite - and maybe it's not even possible. 'Thunderegg' is a fairly informal and non-scientific term, anyway. The structures in this do look to me very much like small coreless thundereggs, at least visually - sufficient for me to at least class them as something similar. I'm sure someone who knows more about geology than I do could say a lot more about this.

c5cm