What MtheGM said.

When I was at school we used to be informed that Ireland had few natural resources - no coal, no iron, just peat in the middle and barren mountains on the outside. Only when I started listening to Radio Eireann in the seventies (even the regular music programmes would carry the occasional folk or traditional song) did I begin to hear about active coal mines, silver mines, gold mines and more. These were still pretty peripheral to the economy, and never on the scale that created whole communities serving the mines as occurred in the UK and elsewhere, but they did exist.

As Michael suggests, there was time enough in the life of the mining industry in the various regions of Britain for distinct language and customs to develop around similar trades and activities.

It's a great song, sing it by all means, but don't sell yourself or your audience short by telling them it's Irish.

Ross