A Stone Matching Exercise - Part 4

A colour match with grey/green Kentish Ragstone

In the end, the contract for restoring Aldershot Town Hall was not won by Triton Building Restoration Ltd. and petrographic analysis, or further investigation of a suitable stone to undertake repairs, was therefore not needed on this occasion.

Various specimens of Kentish Ragstone

The best colour match, between the samples of sandstone from the plinth and the miscellaneous rocks that I have, is with part of one of the samples of Kentish Ragstone that I had obtained from the Hermitage Quarry. Although a siliceous limestone, I don’t think that it would look out of place for small repairs, especially as the glauconite will weather to give a light brown patina.

Colour variation

For the sake of completeness, in what was now just an academic stone matching exercise, I also obtained samples of other glauconitic stones from the Vale of Wardour in Wiltshire - Chicksgrove limestone and Hurdcott Green sandstone.

Chilmark stone used for edging

Along with fine glauconitic calcareous sandstone from the Teffont Mine at RAF Chilmark, which is used as edging in my garden, it provided me with a complete set of stones that have been used for restoration at Salisbury Cathedral and as a replacement for Reigate Stone.

Chilmark stone from the Teffont Mine

I know Reigate Stone only through seeing it used at the church of All Hallows by the Tower, where it was very green, in the Tower of London and a few other historic buildings in the south-east of England, but I have never seen a rock exposure or held a piece in my hand.

All Hallows by the Tower

Whilst used widely in Westminster Abbey, large churches and royal palaces, it developed a reputation from early use for its lack of durability and the last of the Reigate Stone mines, which stretched from Godstone in the east to Brockham in the west - a distance of 10 km - closed in the 1960’s. To the west of Brockham, the rocks are steeply tilted and were unsuitable for mining.

Reigate Stone ribs in the Tower of London