End Crystal

An end crystal is both an item and an entity found in the End.

Natural generation
An end crystal is found atop each obsidian pillar on the central island of the End, each on top of a piece of bedrock. There are 10 end crystals in total, of which two of them are protected in "cages" of iron bars. All end crystals respawn one after another as the respawning process of the ender dragon starts.

Healing the ender dragon
Their primary purpose is to recharge the health of the ender dragon, who gains a charge from the nearest crystal within a cuboid extending 32 blocks from the dragon in all directions. The dragon is healed each half-second. If multiple ender dragons are spawned, an end crystal can affect multiple dragons at the same time. The healing beam is neither obstructed nor is its power diminished by entities or blocks.

Respawning the ender dragon


As items, end crystals may be placed on bedrock and obsidian, if the two blocks above the bedrock or obsidian block are air or replaceable blocks and no other entities intersect the area. If four are placed on the end exit portal, one on each of the flat sides, the crystals respawn the original end crystals on the obsidian pillars, as well as resurrect the dragon itself, before exploding. The top of each pillar also explodes, destroying any player-placed blocks. This happens even if TNT explosions are turned off in settings.

If the exit portal is ever broken for any reason, end crystals can still be placed on obsidian blocks with the same location as the exit portal.

Explosions
End crystals explode when attacked or damaged in most ways, even by attacks that normally do zero damage. They are not affected by exploding fireworks, and if damaged by an explosion, they disappear instead of exploding. The end crystal's explosion has an explosion strength of 6, the same as a charged creeper. Any ender dragon charging from the crystal when it is destroyed takes damage.

Although an ender dragon damages most blocks and entities in its path, it cannot destroy end crystals simply by going near them.

Beams
The end crystal naturally shoots a beam at the ender dragon and heals it when the dragon is within range. This beam can be manually created using the command. The beam can be pointed in any direction, allowing it to mark locations or objects.

Properties


The base appears to be made of bedrock, with a crystal hovering over it. While in the End, a crystal continually generates fire at its current position, one block above the base (directly on top of the block the base is embedded in), replacing any other block at that location. This fire is capable of spreading. The end crystal entity is not solid and can be walked through freely.

End crystals can be pushed by pistons, but they explode if moved while into fire.

ID




Entity data
End crystals have entity data that define various properties of the entity.

Trivia

 * According to Jeb, the reason behind the current crafting recipe using glass as opposed to chorus fruit or any materials introduced in 1.9 is as a means for players to craft end crystals in older worlds that the dragon has already been killed in.
 * Unlike the similarly-explosive TNT, normally hitting an end crystal makes it explode. However, they can be removed safely if they're immersed in water first.
 * Since fire is checked only when an entity moves, end crystals do not normally take damage from their own fire.
 * Oftentimes, the fire remains after an end crystal blows up.
 * A historical rendition of the beacon block featured an animated entity within it, which resembled a yellow miniaturized end crystal. The bedrock platform of the end crystal entity would also render below the beacon, though this would normally be hidden within the block below.
 * Using a piston to push an end crystal's fire into an end portal block deletes the end portal block. However, natural portal blocks regenerate if the end crystal is moved.