Building Stones of Manchester
In bright October sunshine, 25 members and friends met outside the Portland Stone clad Central Library in Manchester for a walk through the building stones of the central part of the city led by Fred Broadhurst, ably assisted by Morven Simpson.
Our route took past some of the older buildings via several of the newest and showed that modern buildings are not all concrete and steel. The stones we saw came from a variety of locations: Scotland, south west England, India, Norway, Portugal and Brazil to name just a few. Some were highly polished, others showed ravaging by the elements. We saw structures, we found fossils and somewhere in between we had lunch!
After looking at the Central Library’s fossiliferous Portland Stone and granite steps (some pink Shap), we turned to the magnificent Midland Hotel with its red brick, red Peterhead and dark Shap Granites.
The steps are made from the highly distinctive Balmoral Red (from Finland - true) with its black and red minerals. Another ‘red’ building followed. this time the Manchester International Convention Centre with its Permian Locharbriggs sandstone. Bedding could clearly be seen which seemed to be determined by grain size.
Passing Rosa Porrino granite (Spain), St Louis nephaline syenite (Portugal), yellow French limestone containing large gastropods and Rapakivi (Baltic Brown) granite left us reeling and glad to reach the warm red Permian Penrith Sandstone of the John Rylands Library.
It was just a pity that the extension has used heat treated copper which doesn’t fit either in look or colour. Sometimes architects don’t get it right.
It was disappointing to note that in Spinningfields Square, it had been considered preferable (read cheaper) to import a silver grey granite from Jinjiang in China than use a British granite for paving slabs. A darker variety has been used in Hardman Square for a water feature which can’t be used because of vandalism.
Walking further along Deansgate we found John Dalton House clad in Burlington Slate. This is Silurian in age and one could see both bedding and slaty cleavage very clearly. The stone in St Ann’s Church was probably the most local stone we saw: it came from Collyhurst, Carboniferous Binney Sandstone. Over the years it has weathered badly and a lot of patching has been done. Unfortunately different types of sandstone, often of better quality, have been used. In the smog-ridden days of the 19th and early 20th century this didn’t really matter. However, the building has now been cleaned and looks rather like patchwork quilt with the different colours, not unpleasant but a bit odd.
Lunch found us in the new Exchange Court (an addition to the Arndale Centre). Here the floor is formed by Verde Maritaca, a Brazilian migmatite where fold structures can be seen. The stone was first folded then partial melted and this can easily be seen. it is however not common to see. Other stones in the area seemed to come from the four corners of the world: Impala Black, a South African basalt, Brazilian Samba white gneiss and Sardinian Grey granite and Jurassic Jura Grey limestone from Solenhofen in Germany. This latter rock had wonderful examples of ammonites, belemnites and sponges together with what are thought to be bacterial masses.
We moved back outside and finally found more British rock: Welsh slate from Bethesda/Nant Ffrancon in purple and green and some Stanton Moor Sandstone. As we walked towards what was the ‘financial’ area but now has lots of cafes and shops, we found Norwegian Larvikite, lots and lots: Blue Pearl and Emerald Pearl plus more Finnish Rapakavi granite. Primark (the old Lewis’s building) had serpentinite in its doorways.
That had proved a mistake: it was badly weathering. Its sheen had gone and it was crumbly. Had it been positioned inside the doors, it would probably have been fine but Manchester weather and traffic pollution have almost ruined it.
After passing some multicoloured gneiss, beautiful pink and black and showing lots of deformation we came across Rapakivi granite showing really good examples of ovoid orthoclase feldspars with concentric inclusions of other minerals.
Our walk finished on Mosley Street where in a doorway one might have otherwise ignored, a beautiful example of Imperial Mahogany could be seen. This is a Precambrian granite from South Dakota. Its distinguishing feature is blue quartz. Yes, the crystals do have a blue hue to them when viewed through a handlens.
We thanked Fred and Morven warmly: it had been a terrific trip and most people are now waiting eagerly to get their hands on the new Building Stones of Manchester book which will be published shortly. Then we can all do the walk again - probably over several days to really have time to take everything in.
Jane Michael
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