XenCraft Mod 1.12.2 adds Xen crystals which can be used to craft different fancy decoration blocks. This mod is a XyCraft inspired mod, but with very different mechanics.
First step is to find the Xen Ore. It doesn?t matter what color you break, it will always drop the same Xen gem.
Next, you craft yourself some Xenstone and a Xen Crafting Table.