worn water nugget in caprock

How does something that's locked in caprock. that you have to chisel out is smooth.

mark 409

Hi Mark, I'd say it's just a water worn alluvial nugget, that originally shed from a reef and rolled down a creek/river. Just that it probably happened a long, long time ago, under a different climate and the river has since been covered, and solidified, then uncovered. It could have happened a few times in succession. It could even be around 3000 million years old if your 'caprock' is real old conglomerate!

Regards
Stingray