Peridot, in my experience, is a happy gem. It is great for depression and mood/even temper and for pessimists or people who have generally "glass half empty" viewpoints may either find it the most reassuring stone in the world, or it may irritate the snot out of them. I deal with a depressive mood disorder, when I'm happy that stone is great, but if I'm in a mood valley, I simply can't deal with Peridot. I don't even want to see it. It tends to not delve into deep emotion imbalance due to things like a mental disorder like other stones can. The best way I can explain it is Peridot is like the person who says "Smile! It isn't as bad as it looks! Smiling will make you feel better!" Sometimes you hear that and you're like "yeah, I do feel pretty good!" and other times you just don't want to hear it.
Since Peridot has so much iron in it, it is great for healing blood disorders or a amulet for surgery where blood loss can be a concern. It's a great, awesome, maybe one of the best (in my experience) gems out there for heart issues, physical and emotional (remembering the warning above). It's great on a necklace for people with heart disease. Of you want 100% anecdotal uses, I find it great for pain relief.
On a psychic level, it enhances empathy and emotional compassion, so that makes it great for introspective meditation or relaxation. I think as a byproduct of that, it is a good protection stone as it encourages peace and putting yourself in other's shoes, but I don't use it as a protective stone on it's own. Same with prosperity concerns... I've never used it for that but that's not to say it wouldn't do well.
I hope that helps!