Dreams dictionary: Colliery (coal-mine)
Dreams dictionary: Miller Dream Interpretation
To dream of being in a coal-mine or colliery and seeing miners, denotes that some evil will assert its power for your downfall; but if you dream of holding a share in a coal-mine, it denotes your safe investment in some deal. For a young woman to dream of mining coal, foreshows she will become the wife of a real-estate dealer or dentist.