Java Edition 21w07a

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

Additions
Has a hardness value greater than that of stone but can be mined with any pickaxe.
 * Grimstone
 * A new type of stone.
 * Generates below y = 0.
 * Functions identical to cobblestone and blackstone in that grimstone can be used to craft basic tools, furnaces and brewing stands.
 * Can be crafted into: 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 and Chiseled Grimstone.

General

 * Blocks
 * Changed the textures of all ores without unique textures except for diamond ore to have different shapes for all ores.
 * Slightly changed the texture of blackstone, polished blackstone bricks, and cracked polished blackstone bricks.


 * 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

World Generation

 * Caves
 * Noise caves and aquifiers 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 altitudes of 0 - 96 and like all other ores, uses spread. It peaks at y = 48.
 * Emerald ore generates between y = 32 - 256 as a spread, peaking at 256 and decreasing in quantity as the altitude decreases.
 * Coal ore attempts to generate twice, once, evenly between an altitude of 136 - 256 and as a spread, peaking at an altitude of 96 and generating between an altitude of 0 - 192.
 * Other ores also generate differently.
 * Iron ore attempts to generate twice. Once as a spread peaking at an altitude of 256, generating between y = 126 - 256 and another as a spread peaking at y = 32 and generating with a minimum height of -16 and a maximum height of 80.
 * Gold ore generates between the altitudes of -60 - 30. It peaks at y = -16.
 * Tweaked size and positioning of diorite, andesite & granite generation
 * Diorite, Granite, and Dirt no longer generate below y = 0
 * Grimstone now generates as the dominant stone below y = 0.
 * Stone still generates, now in small pockets similar to granite, diorite, and andesite veins.
 * Structures
 * Strongholds are now encased in stone
 * Mineshaft corridors are now supported by chains above.