A little bit of Cornwall, in my soul

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Rough-dressed Cornish granite, showing off the minerals beautifully


When you see granite in an urban setting, it's usually a polished slab on the wall of a bank (or former bank which is now occupied by purveyors of mediocre coffee) or rough-dressed as setts.  Sometimes it is scuffed and scratched so still very interesting to look at but not good for photography unless the scuffs and scratches are the subject of the photo.

This particular piece, though, is rough-dressed and at a perfect height for photography.  It's in the wall of an extant bank in Peterborough city centre, UK.  It comes from Cornwall (SW England), and it tells a story:  It is a minute part of the Cornubian batholith which shapes the modern landscape; the said batholith was emplaced some 280 million years ago in the early Permian Period as magma solidified underground after the Variscan mountain-building episode further to the south.  Cornwall is a lovely county, famed for its scenery, it's pasties (a historic local food), and its geology.  I have been lucky enough to visit a number of geological sites in Cornwall  - as well as the Eden Project and the Lost Gardens of Heligan - and a number of places with interesting and very different geology in Devon, the next county to the east. 

The snowy-white mineral making up the bulk of this sample in this photo is plagioclase feldspar, the grey is quartz, and the black and shiny ones are varieties of mica (biotite and muscovite respectively).


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