Bittergem is an extremely rare bonus resource. When extracted and deposited into the M.U.L.E, it can provide between 1000 - 1500 Bittergem units, which is translated to bonus credits, very similarly to Gold. It is a heavy object and must be picked up and carried by hand, or via Bosco. When carrying it, a dwarf cannot do anything but throw flares / throwables, ride ziplines, and move with a 25% speed penalty (Sprinting is also disabled, however the dash active perk is not and provides a nominal speed boost). It can be dropped by switching weapons or using the Laser Pointer, it can also be thrown far away by holding the [FIRE] key ("Left Mouse Click" by default) before releasing it.
Its only use is to provide a large amount of bonuses to Credits. Each unit of Bittergem is worth 1 Credit (total hazard bonus not included).