With the resource pack you can see each compressed state
Piston setup
To compress the coal you need to use a piston that has a beacon block on the end of the piston. Then drop the coal item in front and activate the piston to push the item into the other blocks
![Coal Under Pressure [Datapack Edition]](https://media.forgecdn.net/avatars/thumbnails/449/119/256/256/637708004589747225.png)
