Blue Pool

Blue Pool is a flooded, disused clay pit where Purbeck ball clay was once extracted. It is now a lake within the Furzebrook Estate, a 25acre park of heath woodland and gorse near Furzebrook on the Isle of Purbeck, in the county of Dorset, southern England.Furzebrook Estate is about 5km south of Wareham and 3km west of Corfe Castle.The pool started life early in the 17th century as a chalk pit. Purbeck ball clay was dug from the pit from the mid-17th century to the early 20th century. The ball clay was used to make fine ceramic products, such as smoking pipes, plates, cups and tea pots. The pit became disused before the First World War, but ball clay is still extracted from other pits in the area. The title 'blue' arose because there are minute particles of clay in colloidal suspension within the water. These suspensions variously diffract the light depending on the particles' size (with differences in size often linked to changes in concentration and pH), yielding colours from red-brown, through grey and green, to the more typical turquoise. The metallic blue sometimes found in photographs is more likely to be a reflection of the sky, as the attraction's own website makes no such claim for the water, and their leaflets call it “a turquoise jewel set in the heart of Purbeck”.