My first gem staff and Real Magic Weapon was an Emerald staff that took entirely too long to get the emeralds for, but I wasn't willing to settle for anything less. It was amazing. Moving light source, decent damage, hits two enemies, low mana cost, and a beautiful verdant color... It had everything.
Then I finally got enough meteorite for a space gun and meteor armor. After I upgraded to crimson armor I put it back in my hotbar, but that was the beginning of the end. I'm far into hardmode now and my poor Emerald Staff sits in a chest collecting dust. I think I need a wallmount for it, to honor its long and distinguished service.