This concretion was collected a few days ago, August 2021. The location is a quarry at Bwlch-y-Sarnau in Powys. The detail in this cone in cone variety of concretion is outstanding, with high detail in the cross section, and very pronounced cone tops. It appears to be a broken section of a much larger rock. The detail is so clear that the specimen could be a helpful aid in understanding the formation and growth of concretions.