Slate

Slate blocks are found in taiga biomes in large clusters like gravel. It looks like gravel, but with larger, thin plate-like chunks. It acts mostly like gravel, but with different conditions on which it falls. Slate will only fall if enough weight is on top of it, and more layers of slate can carry more weight. Slate blocks break into gravel upon hitting a non-solid block. You can find flint in slate, (like gravel) but only if you are using a shovel.

The slate item can be mined from slate using a silk-touch shovel or pick. Slate can be crafted into writing slates, which are like signs you can edit. These require dye, pumice, or some chalk-like block to write on or edit. Writing slates are placed similarly to item frames rather than signs, and join together when on adjacent blocks to form larger writing slates. Slate can also be used to repair any item, though only by one 16th. This disenchants the item, you get half the Exp you would have gotten from a grindstone. Slate can be used as flint in arrows, or crafted into a slate block.