In Reply to: PYRIDE? posted by Ellison on March 14, 2014 at 09:19:40:
Pyrites? A nasty contaminant if used in foundations of buildings as it takes up water and reacts expanding and causing huge cracks in the building.
Not sure that it's a tourist attraction though :).
A number of quarries in the NE of the country appear to be the main sources. Lack of regulation during the Celtic tiger - build build build.