Gamer Corner Guides

Gems allow you to view a map of the world, the towne you're in, or the current dungeon level. All of these are useful purposes, but there are spells that do the same and don't cost 75 Gold, and plus this site provides all the maps you'll need.

That said, Gems aren't useless. You can locate the whirlpool with a Gem, or figure out exactly where you are in a dungeon if you get lost. Just don't waste them, because they aren't cheap.