In the fictional Star Trek universe, the Omega particle is an extremely unstable molecule with enough internal energy to destroy a civilization. Strangely enough though it can be destroyed using explosives.

The Borg refer to it as Particle 010 and consider it a model of perfection as it is made up of enormously large numbers of atoms in a very complex pattern making one stable whole.

Because of the dangerous nature of the particle all Starfleet admirals and captains have a standing order, the Omega Directive, to destroy all Omega particles.