It'll probably have a slightly diminished force, owing to the fact that a smaller crystal won't be able to hold up to as much energy before hitting the critical threshold and exploding as a larger one would. However, it's not like the sum total of energy is a fixed number and it ends up divided evenly among the shards; two half-shards would still explode at roughly the same violence as one big one, but eighteen tiny shards wouldn't.

Does that make sense?