This has probably been suggested before, but I didn't get any obvious hits with a quick search, so here we go.
I'm hopeless at remembering which mineral equal what kind of ore, and which are just pretty stones. In practice this means the game is frustrating to play without the DF wiki open at all times.
Eventually I suppose it would be nice to have a kind of Civopedia-style ingame reference system, so that when you get the "You have struck Mineral X!" message pops up, there's a "What's this?" button that brings to a short and helpful description of the mineral. Not sure if something like this is planned, but the current popularity of the wiki and the fact that many feel the game is nigh impossible to get the hang of without it I guess it'd be a good idea to integrate something like that into the actual game eventually.
Anyway, in the absence of something like the above (and regardless of it), would it be possible to have the "You have struck [stone]!" message tell me more explicitly what I've just found? E.g. "You have struck Garnierite (Nickel Ore)!". I love the fact that the game differentiates between so many different kinds of ores and stones, it makes the whole mining experience much more immersive, but it does obfuscate things.
In the same vein (heh) it might be helpful if the jobs in the smelters explicitly said what kind of metal bar will be produced, i.e. "Smelt Limonite Ore into Iron Bars" instead of just "Smelt Limonite Ore".