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.

Blocks

 * Grimstone
 * A new type of stone.
 * Generates below Y=0.
 * Takes over fully underground starting from Y=-8.
 * Will have a gradual transition from stone to grimstone as the Y-level reaches 0.
 * 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.
 * It can be crafted into many different variants.
 * Has a hardness value greater than that of stone but can be mined with any pickaxe.

General

 * Data Packs
 * Added to.

Blocks

 * Blackstone, polished blackstone bricks, and cracked polished blackstone bricks
 * Slightly changed the texture.


 * Ores
 * The textures of coal ore, diamond ore, gold ore, iron ore, and redstone ore have been changed.
 * All ores except diamond had the shape of the "ore pattern" in the stone changed to make them visually distinct.

World generation

 * Caves
 * 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 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 -16 and a maximum height of 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 becoming more common at lower depths.
 * 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, and dirt no longer generate below Y=0.
 * Grimstone now generates as the dominant stone below Y=0.
 * Andesite still generates unlike stone, diorite, granite, and dirt.


 * Mineshafts
 * 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.


 * Strongholds
 * Are now encased in stone and/or grimstone, depending on the depth.

General

 * 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


 * Tags
 * Added grimstone to the block tag and the  item tags.
 * Added various grimstone variants to the block and item tags.

Video
Videos made by slicedlime: