A mine is a location at which the primary industry of mining takes place - that is, a place where some mineral is dug out of the ground (however, stone and aggregates are traditionally dug from a quarry instead and liquids and gases are extracted from wells rather than mines).
How mining is performed depends on the culture and the nature of the deposits they are working - primitive cultures tend to work by open cast mining of shallow deposits … that is they strip a thin layer of soil off the top of the material they want and dig it out (although this technique is still used at more advanced levels for large volumes of material at shallow depths). As technology evolves, the miners can dig deeper through harder rock for their choice of material - and the more valuable the material, the deeper people are prepared to dig.
Even in the modern era mining is a dangerous business with errors deep underground leading very easily to serious consequences and the integrity of the mine itself threatened by unstable ground and the ingress of water and hazardous gases … fantasy settings are likely to add all manner of unpleasant things hidden below the ground that are traditionally disturbed by over zealous mining. Depending on culture miners may be rugged individualists through to short lived and miserable slaves. History has known many free miners, and many mines that have swallowed the lives of countless slaves … in between the two, a feudal fief may have serfs obliged perform their corvee levy in the lord's mines rather than his fields.
Abandoned mines are even more fun - the deeper ones are liable to fill with water if not constantly pumped out, whilst all sorts of things might take up residence and the timbers supporting the galleries will almost certainly have degenerated.
The placer mine in which granules of metal are sorted from bodies of water by sieving is a marginal case, although gold in particular has been often mined by hydraulic mining where gold-bearing strata are deliberately eroded by channelled water and the run-off processed by scaled up placer methods.
Material extracted from a mine which does not contain the target material is known as tallings or spoil and is generally piled nearby in spoil heaps. These can be a significant sign of mining activity and become terrain features in their own right. Optimistically they may be used to re-fill the workings afterwards, but are more like to be left where they are. Sometimes a change in emphasis or an increase in technology may mean that the spoil tips from a mine can be (re)processed to extract more or different material (for example extracting lead from the tallings of many silver mines or modern biological techniques now used to extract far more material from old gold spoil).
Game and Story Use
- Abandoned mines make good starter dungeons.
- Clearing a mine can make a good project for a party - especially if they happen to own the deeds.
- Poorly maintained spoil heaps may collapse unpredictably.
- As noted above, a mine may tap into all sorts of things.
- Mines can be extremely strategic locations - wars have frequently been fought over rich gold mines, whilst during a war mines providing iron or tungsten may be key.
- Mining culture should also be an important consideration when designing your setting - are your miners one man bands, as in the early days of the California gold rush, or the heyday of the Forest of Dean's iron and coal period? Are they partners in joint venture companies? Employees? Exploited serfs or wage slaves or outright chattle slaves?
- The undead might make good miners under some circumstances as well - not only do zombies not need to be paid or fed, they don't need light, rest or air either (assuming that they can work without human supervision). Even where skilled miners are needed for some tasks, the dead might have some role to play in the grunt-work.
- After the end, communities are sometimes shown mining the garbage dumps of their ancestors, searching for valuable materials (actually, before the financial crash bit, there were quite a few places where waste companies were sampling their old landfills to determine if there was enough valuable material - especially metals such as copper