Concretions are very common in the mudstones of the Welsh basin. Most of them are found without an apparent mineral content. There are exceptions with an occasional calcite core. This specimen, which has an infilling of calcite is the only septarian concretion that I have observed in central Wales. It was discovered at Abermule, very near to the river Severn, 6Km NE of Newtown. This area is on the outer margins of the Welsh basin, and septarian concretions are known to form at relatively shallow depths of water and sediment.