Explosive decompression comes from internal pressure overcoming its container, where the pressure within the container is greater than without. The core of a pl

Explosive decompression comes from internal pressure overcoming its container, where the pressure within the container is greater than without. The core of a planet is pretty much the opposite, where the pressure is coming from the outside and smushing things together. I know it seems similar, but it isn't really. You know how diamonds do not "explosively decompress" (explode) after they are formed? Think of it more like that. Popping the core out of the centre of a planet intact would be your bigger challenge, I think. A collision with enough force to crack open a planet down to its core is probably not going to leave the core crystal intact.