Hull Geological Society
Common urban rocks -
(a work in progress)
Grey Igneous Rocks
There are a number of grey medium or coarse grained igneous rocks use to decorate buildings or as monuments and gravestones. They are not easy to identify just from their appearance.
The very pale grey coarse grey rocks are probably granites. The very dark grey or black rocks are probably Basalt, Dolerite or Gabbro.
Diorites are grey and white rocks, sometimes with dark xenoliths (remains of country rock that fell into the magma.
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