This was done with peaceable craft able crystals, not the crystals in the end.

Java Results

As the difficulty of the game scales up ie. Easy, Normal, Hard mode, the damage of crystals does so as well.

Bedrock Results

All modes of difficulty have the same crystal damage, which is equal to the damage on Easy Mode in Java Edition which leads me to believe this is a bug because nothing about it is mentioned in the Wiki.

Summary
Bedrock Edition Hard/Normal/Easy Mode Crystals do the same damage as Java Easy Mode crystals whereas it should scale up and be equal in damage across the games.