Java Edition 21w10a

21w10a is the thirteenth snapshot for Java Edition 1.17, released on March 10, 2021, which adds lush caves and new deepslate variants.

Blocks

 * Cracked Deepslate Bricks
 * Added a cracked variation of deepslate bricks.


 * Cracked Deepslate Tiles
 * Added a cracked variation of deepslate tiles.


 * Deepslate Ore
 * Added the deepslate ore for copper, emerald and coal ore, but they will not generate in the world by default, they only have been added for use by creators of maps and data packs.


 * Infested Deepslate
 * An infested variant of deepslate.

World generation

 * Azalea Tree
 * Generate above lush caves, either on surface or underground.
 * Consist of azalea leaves (both variants), oak logs and rooted dirt.


 * Lush Caves biome
 * Currently the biome is only accessible in single-biome worlds.
 * Adaptive to the environment: every type of cave generation can be a lush cave.
 * Moss covers the floors and ceilings, along with moss carpets and grass on the floors.
 * Spore Blossoms grow from the ceiling and drip particles.
 * Contains clay pools where dripleaf plants grow out of them.
 * Contains azalea bushes (both variants).
 * Cave vines with glow berries grow from the ceiling and light up the caves.

Blocks

 * Cobbled Deepslate
 * Can now be smelted back into deepslate.


 * Deepslate
 * The texture has been changed.
 * Deepslate can now be placed along any axis.
 * Textures in caves now generate with a random rotation.


 * Deepslate Bricks and Deepslate Tiles
 * Can now be crafted.


 * Ores
 * The textures of some ores have been updated.

Items

 * Spyglass
 * The item model has been changed back to a dedicated texture.

Mobs

 * Slime
 * The maximum size that slimes can be summoned with is now 128.

World generation

 * Fossils
 * The fossils in the deepest part of the underground generate with Deepslate Diamond Ore instead of Coal Ore.


 * Ore distribution
 * Now generates more emerald ore in mountains.
 * Now generates more lapis lazuli ore.
 * Now generates less copper ore, gold ore, and redstone ore.
 * Now generates smaller diamond ore blobs, but slightly more frequent (less diamond ore overall though).
 * Now generates less iron ore, and it generates lower down.
 * Reduced air exposure for coal ore.

Command format

 * The give command can only give up to 100 stacks of items at a time (e.g. 6400 stone or 100 iron swords)
 * The give command can only give up to 100 stacks of items at a time (e.g. 6400 stone or 100 iron swords)

General

 * Game library updates
 * The game now runs using OpenGL 3.2 core profile.