Java Edition 21w16a

21w16a is the eighteenth snapshot for Java Edition 1.17, released on April 21, 2021, which adds dripstone growth to the game.

World generation

 * Ore veins
 * Large rare snaking collections of ore found underground.
 * Copper mixed with granite is found at and above Y=0; iron mixed with tuff is found below Y=0.
 * Only available when Caves & Cliffs features are re-enabled via data pack.

Gameplay

 * Pointed Dripstone growth
 * If a stalactite is hanging from a dripstone block with a water source above, it will slowly grow both the stalactite from above and a stalagmite from below.
 * Growth speed is random but very slow; a single growth step can take several in-game days.
 * A stalactite will only grow up to 7 blocks long.
 * A stalactite will only cause stalagmite growth if the floor or stalagmite below is within 10 blocks.
 * If the stalactite tip is inside water it won’t drip, and therefore will not trigger any growth.
 * If the stalagmite tip is inside water or their is a fluid between the two dripstone blocks, it will not receive the water drops, and therefore will not be grown by a dripping stalactite.
 * A stalagmite or stalactite will never grow into a fluid.

General

 * Tags
 * Added the block tag.
 * Contains the #base_stone_overworld block tag, the #cave_vines block tag, and the #dirt block tag.

Blocks

 * Azalea and Flowering Azalea
 * Can now be bonemealed to form Azalea Trees.


 * Block of Raw Iron and Block of Raw Gold
 * Tweaked the textures of these blocks.


 * Infested Deepslate
 * Can now have random texture rotation like deepslate.


 * Small Dripleaf
 * The model was slightly changed.

Items

 * Raw Metal
 * Tweaked the texture of raw ores.

World generation

 * Aquifer
 * Aquifers below Y=0 will now be made of lava.
 * Only available when Caves & Cliffs features are re-enabled via data pack.

Gameplay

 * Recipe Book
 * The recipes for stonecutting diorite into polished diorite slabs and stairs now unlocks when the player has diorite as opposed to polished diorite.

General

 * Statistics
 * Renamed the statistic for play time to.
 * Included time when game paused for "Time with World Open".


 * Resource pack prompt
 * Users who previously permanently declined server resource packs will now still be shown the pack prompt if the pack is mandatory, instead of being immediately disconnected.


 * Tags
 * Added grass blocks, mycelium, and moss blocks to the block tag.
 * Tweaked some tags to no longer unnecessarily mention blocks if they're in the dirt block tag.
 * Tweaked the block tag to call the  tag instead of the  tag, as well as adding gravel and sand.
 * Removed the block tag.


 * Textures
 * Removed the unused texture.
 * Removed stray pixels from the recipe book GUI button.