Minecraft: Java Edition 21w07a snapshot adds grimstone, tweaks cave generation from 'Caves and Cliffs Update'

Minecraft Caves and Cliffs Update Image
Minecraft Caves and Cliffs Update Image (Image credit: Mojang Studios)

What you need to know

  • Minecraft: Java Edition tests future updates through "slices" of updates called snapshots.
  • The latest snapshot is 21w07a, which is rolling out today with some new features from the 'Caves and Cliffs Update.'
  • Alongside changes to the recently updated cave generation, Minecraft is also introducing the new "grimstone" block.
  • Players can take a look at the latest snapshot now and give Mojang Studios feedback on the changes and features.

Minecraft is rolling out a new snapshot today in the form of Minecraft: Java Edition Snapshot 21w07a. Last week's snapshot was already major and added the brand-new cave generation features being introduced in the upcoming Caves and Cliffs Update. Today, Mojang Studios is tweaking the cave generation while adding a brand-new deep-underground block called "grimstone."

The Caves and Cliffs Update is the next major update for Minecraft, and is expected to release sometime in Summer 2021. Minecraft is busy testing the update in its early stages through Minecraft: Bedrock Edition betas and Minecraft: Java Edition snapshots.

If you want to get the most out of Minecraft: Java Edition, consider one of the Best Gaming Keyboards for PC to upgrade your setup. Minecraft fans can also grab something from the Best Minecraft Merch, Toys, and Gifts for themselves or a fellow Minecrafter in their lives.

The full changelog for Minecraft: Java Edition Snapshot 21w07a includes:

New features

  • Added Grimstone!


  • Grimstone can be found in the deepest parts of the underground and is slightly tougher to mine than normal Stone
  • Like Blackstone, Grimstone can be used to craft basic tools, furnaces and brewing stands
  • You can craft the following blocks with this new stone type:
    • Grimstone Slab
    • Grimstone Stairs
    • Grimstone Wall
    • Polished Grimstone
    • Polished Grimstone Slab
    • Polished Grimstone Stairs
    • Polished Grimstone Wall
    • Grimstone Bricks
    • Grimstone Brick Slab
    • Grimstone Brick Stairs
    • Grimstone Brick Wall
    • Grimstone Tiles
    • Grimstone Tile Slab
    • Grimstone Tile Stairs
    • Grimstone Tile Wall
    • Chiselled Grimstone


  • Tweaks and updates to world generation and ores
  • Changes to the visuals of some ores and stone types
  • Reordered Redstone Tab in Creative Inventory

World generation

  • Tweaked huge caves to be more rare and decreased the chance that caves are filled with water
  • Changed ore generation to match the new world height and to add more strategy to mining
  • Tweaked size and positioning of diorite, andesite & granite generation
  • Exception: Diorite and Granite and Dirt no longer generate below y = 0
  • Strongholds are now mostly encased in stone
  • Mineshaft corridors are now supported by log pillars below or chains above when needed


  • Ores without unique shapes have been given new textures for accessibility reasons, so that each ore is distinguishable by shape alone
  • Being the most iconic ore, Diamond Ore texture is staying the same to keep that classic feel maintained
  • Blackstone, Polished Blackstone Bricks, and Cracked Polished Blackstone Bricks have had some minor touch-ups

Creative inventory

  • The Redstone Tab has been reordered to prioritize highly-used blocks
  • Redstone items / blocks have been grouped and ordered in the following way:
    • Essentials
    • Unique activators
    • Miscellaneous
    • Common activators
    • Openables

Bug fixes

  • Vines no longer randomly generate in jungles
  • Amount of players who need to sleep to skip the night is calculated incorrectly
  • Clicking on a bed immediately skips the night if gamerule playersSleepingPercentage is set to 0
  • Seagrass can occasionally replace parts of a swamp hut
  • Crash after placing soul sand or magma under 2032 tall water
  • Strongholds generate floating and without walls, floors, or ceilings when inside caves
  • Bedrock can be exposed to the air at the very bottom of the new caves
  • Beacon beam only render 256 blocks from source
  • Powder snow bucket in a dispenser at y = 319 facing upwards or at y = -64 facing downwards is replaced with empty bucket, despite no powder snow being placed
  • Large dripstones only generate as stalagmites below Y=0



Zachary Boddy
Staff Writer

Zachary Boddy (They / Them) is a Staff Writer for Windows Central, primarily focused on covering the latest news in tech and gaming, the best Xbox and PC games, and the most interesting Windows and Xbox hardware. They have been gaming and writing for most of their life starting with the original Xbox, and started out as a freelancer for Windows Central and its sister sites in 2019. Now a full-fledged Staff Writer, Zachary has expanded from only writing about all things Minecraft to covering practically everything on which Windows Central is an expert, especially when it comes to Microsoft. You can find Zachary on Twitter @BoddyZachary.