Shadow block crystal

The shadow block crystal is a green crystal crafted like this

Slime = s

Shroomlight = sh

s s s

s sh s

s s s

Or you could use it by enchanting a crystal, crafted like this

sea lantern = sl

sl sl sl

sl sl sl

sl sl sl

Then you use a shadow block enchanted book and put them on the anvil together

To use the shadow block crystal you just tap and hold on a block of your choice, like your trying to break it, then the shadow block crystal leaves your inventory like it was never there, if you do the same to make a 2x1 rectangle that you can walk through, you can then walk right through the block that you used the crystal on. 

Using this crystal is very useful for making a secret base, as long as you can remember where you put it!

(Also you can’t mine a shadow block making it a lot easier to make a base, also so that it’s not completely impossible to find it)