Added:

Any player within 5 blocks of a player breaking gems will recieve half the amount of EXP, players further than a 5 block radius from the gem break will get nothing

Dragons Essence - Obtained via the admin menu or defeating the Ender Dragon. EXP: (800 - 1000)

Heroic Gem - Gained by mining Ore or killing Mobs EXP: (200 - 500)

Changes:
Updated admin menu.
added more configuration for Mining ore chances.

revamped the default chances of all gems to be more forgiving (though you can change to your will)