Re Ireland having no natural (mineral) resources- as someone else said, the Arigna area of North Roscommon /Leitrim had a thriving small-scale coal industry- drift mines rather than deep mines. Thereis still a tourist attraction in Arigna called the Mining Experience' and one of Irish music's greatest ever flute players, John McKenna worked at the Arigna mines before heading off to fame in New York.

also. what about...
'And in Kilkenny it is reported
There's marble stones there as black as ink'

(from 'Carrickfergus'- a very old song)- any local knowledge?