Starting at level 2, Bomb Gems will begin to appear. Bomb Gems have dull metallic outer casings and a large number on the front. The number decreases by 1 after every move, regardless of whether you make a match or not. If the number counts down to zero, a warning klaxon will sound and you will be given an opportunity to disarm the bomb (see Disarm Spinner). Bomb Gems can be twisted and matched like any other gem, or destroyed by Flame or Lighting Gems. Bomb Gems are destroyed at the end of each level.
Bomb Gems do not appear in Zen mode.