Hard Rock Miner's Handbook

[thrash]

More science (or engineering) in your fiction:

Hard Rock Miner's Handbook

This free pdf file is a compilation of articles on the real-world mining industry. Each chapter begins with a page or two of "rules of thumb" and "tricks/tools of the trade" -- just about the right level of detail for role-playing purposes.

There are some interesting tidbits, as well: dungeon designers may want to look at the sections on natural ventilation (p. 165) and drainage tunnels (p. 193). The section entitled "Source of Slimes" (p. 190), sadly, concerns particles suspended in drainage water, rather than gelatinous life forms.

[sir_pudding]

The title suggests Brütal Legend-esque settings.

Dwarven Prospector: "This ore is of the hardest rock, and will produce the heaviest of METAL, for your righteous axe!"

[thrash]

Spelling matters. The "Hard Rock Minors' Handbook" would be a very different resource.