Minecraft Wiki
Minecraft 21w07a
Java Edition 21w07a.png

Java Edition



Release date

February 17, 2021

Snapshot for



Client (.json)

Obfuscation maps


Protocol version

 dec: 1073741839
 hex: 4000000F

Data version


21w07a is the tenth snapshot for Java Edition 1.17, released on February 17, 2021,[1] which adds grimstone and tweaks ore and cave generation.



  • A new type of stone.
  • Generates below Y=0.
    • Has a gradual transition from stone to grimstone starting from Y-level -1 until it reaches -8.
    • Takes over fully underground starting from Y=-8.
  • Functions identical to cobblestone and blackstone in that grimstone can be used to craft basic tools, furnaces and brewing stands.
  • Can be used as a decorative block.
  • Has a hardness value greater than that of stone but can be mined with any pickaxe.
  • Can't be insta-mined unlike stone.


Data Packs
  • Added  grimstone_enabled to worldgen/noise_settings/*.json.



Big dripleaf
  • Slightly changed model.

The new ore textures.

Blackstone, polished blackstone bricks, and cracked polished blackstone bricks and stair, slab and wall variants
  • Slightly changed the texture.
Glow Lichen
  • Can now naturally generate on grimstone.
  • Beacon beams are now visible up to 1343 blocks away from the source instead of 256 blocks.

World generation[]

Ore distribution changes.

  • Noise caves and aquifers appear less often.
Mineral distribution
  • Changed ore generation of all ores making them have a spread value like lapis lazuli ore. Some still retain a linear generation alongside a spread generation.
  • Coal ore, emerald ore, and copper ore no longer generate below Y=0.
    • Copper ore generates between the Y=0 and Y=96 and like all other ores, uses spread. It peaks at Y=48.
    • Emerald ore generates above Y=32 (up to Y=480 in custom worlds) as a spread, peaking at Y=256 and decreasing in quantity as the altitude decreases.
    • Coal ore attempts to generate twice: once, evenly between an altitude of Y=136 and Y=256; and as a spread, peaking at an altitude of Y=96 and generating between an altitude of Y=0 and Y=192.
  • Other ores also generate differently.
    • Iron ore attempts to generate twice: once as a spread peaking at an altitude of Y=256, generating above Y=128 (up to Y=384 in custom worlds); and another as a spread peaking at Y=32 and generating with a minimum height of Y=-16 and a maximum height of Y=80.
    • Gold ore generates between the altitudes of Y=-64 and Y=32, peaking at Y=-16. The extra gold that generates in the badlands biome was left untouched.
    • Lapis lazuli ore attempts to generate twice: once, as a spread between the altitudes of Y=32 and Y=-32, peaking at an altitude of 0; and evenly between an altitude of Y=64 and Y=-64, generating buried like ancient debris.
    • Redstone ore attempts to generate twice: once, evenly between an altitude of Y=15 and Y=-64; and as a spread, peaking at an altitude of -64 and generating below an altitude of Y=-32 (down to Y=-96 in custom worlds).
    • Diamond ore now generate as a spread, generating below Y=16 and peaking at altitudes near y = -64.
  • Tweaked size and positioning of diorite, andesite & granite generation.
    • Pockets of diorite, granite and andesite are now larger and more spherical but less common.
    • Diorite, granite, gravel and dirt no longer generate below Y=0.
  • Grimstone now generates as the dominant stone below Y=0.
  • A 1.17 Mineshaft with ceiling supports and oak log supports from the ground

    A 1.17 Mineshaft

    Corridors are now supported by chains and oak fences above when the layer is nearer to the ceiling than the floor.
  • Wood pillars are now made of logs instead of wood.


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 (from top to bottom): Essentials, Unique activators, Miscellaneous, Common activators, Openables.
Data Packs
  • Vanilla configured features for ore types have changed:
    • Coal and iron have been split into two parts called _upper and _lower
    • New lapis configured feature: ore_lapis_buried
  • The glow_lichen feature now lists grimstone as a valid block.
  • Changes to the range decorator configuration:
    • bottom_offset, top_offset and maximum fields removed
    • Replaced with bottom_inclusive and top_inclusive which are both a new type of vertical anchoring
    • This type can have several forms:
      • absolute - specifies an absolute y value
      • above_bottom - specifies an offset above the minimum y coordinate of the world
      • below_top - specifies an offset below the maximum y coordinate of the world
  • The range_biased and range_very_biased feature decorator are now called range_biased_to_bottom and range_very_biased_to_bottom respectively.
    • Both biased types of ranges now have bottom_inclusive and top_inclusive of the same type, and a cutoff value that's a numeric value
  • The depth_average decorator also now has its baseline field as a vertical anchor instead of an absolute y value.
  • A whole range of decorators no longer exist or have had part of their functionality replaced by using some of the already existing generic decorators:
    • dark_oak_tree decorator no longer does a heightmap check, needs to be done with a heightmap decorator
    • The end_gateway decorator has been split, now used with a combination of chance, square & heightmap - see the end_gateway configuration in the vanilla pack for an example
    • The glowstone_blob feature no longer does its own decoration, instead is used with a combination of square & range. See glowstone_extra in vanilla files for example.
    • The lava_lake feature has also been split, now used with chance, square, and range_biased_to_bottom. See lake_lava for an example.
    • The water_lake decorator has been removed. Now instead chance, square & range
    • The emerald_ore decorator has been removed. Now instead count, square & range
    • The fire decorator has been removed. Now instead range, square & count
    • The carving_mask no longer has a probability field, replaced with a chance decorator
  • Added grimstone to the base_stone_overworld block tag and the stone_crafting_materials, and stone_tool_materials item tags.
  • Added various grimstone variants to the slabs, stairs, and walls block and item tags.


13 issues fixed
From released versions before 1.17
  • MC-125675 – Seagrass placed on the ocean floor can replace ocean monument parts.
  • MC-147589 – Vines no longer randomly generate in jungles.
  • MC-183547 – Stone and polished blackstone buttons/pressure plates are located at opposite ends of the spectrum of buttons in the Creative inventory despite being identical in behavior.
From the 1.17 development versions
  • MC-208613 – Amount of players who need to sleep to skip the night is calculated incorrectly.
  • MC-208618 – Clicking on a bed immediately skips the night if gamerule playersSleepingPercentage is set to 0.
  • MC-211224 – Seagrass can occasionally replace parts of a swamp hut.
  • MC-214082 – Crash after placing soul sand or magma under 2032-block-tall water.
From the previous development version
  • MC-214814 – Strongholds generate floating and without walls, floors, or ceilings when inside caves.
  • MC-214885 – Beacon beam only render 256 blocks from source.
  • MC-214917 – Lapis Lazuli doesn't generate on the lower levels of the world.
  • MC-214928 – Mineshaft corridor support pillars are made out of wood, not logs.
  • MC-214973 – 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.
  • MC-214986 – Large dripstones only generate as stalagmites below Y=0.


Videos made by slicedlime: