Purbeck Stone

Polished Purbeck limestone

Apart from Reigate stone, which was brought to London overland, all of the mediaeval building stones seen at the Tower of London were transported along the River Thames by water – from Maidstone via the River Medway and from various places on the south coast of England – and it was therefore no surprise to discover that Purbeck stone from Dorset has been used in places.

The geology of the Isle of Purbeck

 

Perhaps best known where it has been polished and used in the columns and shafts in mediaeval cathedrals throughout England, this dense and hard wearing limestone is also suitable for paving, as well as for general walling stone - as seen at Corfe Castle.

Purbeck stone used for walling at a stone trade exhibition stand

After my exploration of the walls and towers, I was descending the stairs behind St. Peter Ad Vincula Royal Chapel when I noticed a section of walling that contained a jumble of different stones – including flint – but which essentially comprised a lower section of Kentish rag rubble, with the upper section being thinly bedded Purbeck limestone.

Kentish ragstone and Purbeck limestone walling

Although its rough and weathered surfaces showed none of the colours that can be seen when Purbeck limestone is polished, the Vivaparus gastropods that it contains are still quite distinctive. This was the only time that I saw the Purbeck limestone used as a general building stone but, now that I knew to keep my eyes open for this material, it wasn't long before I saw another example of its use – for paving setts - when exploring the Inner Ward.

Purbeck limestone paving setts