Malachite

Malachite is a multi-target special gem created by combining Chipped Opal ,Chipped Emerald, Chipped Aquamarine. It is one of the two possible gems you're guaranteed to get on wave 1 in Survival or Extreme modes; outdamaging silver though lacking slow effect and impacting game CPU usage more heavily. It can be upgraded twice.

Due rounding issues, 114 range isn't perfectly symmetric. Malachite can hit all areas covered by dark green overlay: Strategies that take malachite may end up it as its major damage dealing gem, and as such maximizing kills on it is matter of interest. It's possible to delay upgrading chances to focus lots of kills on malachite as possible (though this lowers odds of getting past wave 196 due less perfect gems): (Image by 216)

Naturally, this Malachite wouldn't be able to get past wave 12 without being upgraded; defeating flyers without that requires more central gem support.