Mordor gravel is a black block that spawns in patches in Mordor and related biomes. The biome Dagorlad is primarily composed of it. Like normal gravel, Mordor gravel is affected by gravity, but has a separate, darker texture than its vanilla counterpart. It does drop flint. The block was added in Public Beta 21, along with Mordor dirt, in order to randomize and improve Mordor terrain generation. Mordor gravel cannot be crafted into pebbles.
SlabsEditAs of Public Beta 29, slabs are used to create smoother roads, and it's also possible to create them, using a normal crafting table and the standard slab recipe:
|The Spawn of Mordor|
Black Uruk (Archer) •
Orc (Archer, Banner Bearer, Bombardier)