In the old Gaelic political system, Ireland was divided into four provinces: Connacht, Leinster, Munster, Ulster. At present Ireland consists of 26 (29) counties.
References:- Greg, R.P. and Lettsom, W.G. (1858) Manual of the Mineralogy of Great Britain and Ireland. London, 483 pp.
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http://www.mhti.com/ (Mining Heritage Trust of Ireland)
1151 entries listed. 247 valid minerals. 3 type localities (valid minerals).