Mining is a skill used to unearth ore/gems from a rock formation using pickaxes and prospecting to help discover them. Ore, also called nodes, can be found by looking for mysterious rock formations with colored rock, or gems stick out of it. Minecraft, RuneScape and World of Warcraft are games that have Mining as a common skill.
In Gun, Colton can mine Gold from any nodes he sees, but he'll need to pick up a pickaxe from Dodge City.
Mining is one of the many F2P skills found in RuneScape. All that is required is a pickaxe. Once you mine ore, you can Smelt it to turn it into bars to make weapons.
World of Warcraft
Mining is a gathering profession in World of Warcraft. It pairs well with Jewelcrafting, Engineering, and Blacksmithing. A unique feature is the ability to track Ore using your minimap to find nodes within a 50 yard radius (approx).