The tears that fall from crying obsidian have a surprising amount of magical power.
Make sure to get at least Patchouli-1.16-37-FABRIC.jar, if it does not say fabric it is for forge.
To start, a guide for these powers can be found by using a book on the block in question. From there, craft yourself a silver crucible and do some experiments. This guide book, the ingame recipe book, and many advancements are arranged to lead you forwards.
Create large rune arrays that can teleport, heal, move blocks, change mob spawners, and give you new abilities.
Collect tarot cards made from the souls of your enemies.
Build invulnerable walls out of magical power.
All from the tears that collect in a crucible.