If you're really stuck, and would like to experience quite how dark it can be inside a mine, pop down to the National Coal Mining Museum just off the M1 between Barnsley & Wakefield, they'll take you down a lift shaft and into the coal mine.
I went there as a child, but these days it gives me the willies!
https://www.ncm.org.uk/ "Take a tour and, before you go underground, stride out over the Lamp Room’s new glass-topped Furnace Shaft and peer down 140m - right to the bottom of the mine!"
Geology:
the study of rocks & similar substances (minerals n such) that make up the Earth''s surface.
Minerals:
are the building blocks of rocks. They are a naturally occuring,inorganic, solid, crystalline substance which has a fixed structure. (and some of them are really pretty)