Grognardia has a nice review of All the Treasures of the World: Gems here. Depending on the campaign you run, it might be a handy reference piece, but that is often hard to know without taking a peek for oneself. It is not the usual RPG supplement.
Faster Monkey Games has a free sample from the product available here. Check it out and see if it works for you.
(back to the Paladin grindstone)