Crystal of life

It looks somewhat like a lighthouse. Imposes a weak regeneration effect in a 10 block radius and dissolves (kills) undead. Exhausts light for 8 units. The crystal cannot be destroyed or somehow moved. But if you use some kind of explosive more powerful than dynamite, you can achieve the complete destruction of the crystal.

Crystal cannot be crafted in any way, only found in caves.
The maximum crystal generation height is 20 Y. It is also quite rare, about 1 in 90 chunks. A crystal is generated in a small abandoned altar in a cave.

It is impossible to break the block under the crystal, as the roots penetrate it. Crystal can be placed on any surface, even on the ceiling. The crystal itself looks like amethyst, but is 1.5 blocks high and slightly blue.

(Sorry for my English)