Affects Version/s: Minecraft 1.13-pre2
Fix Version/s: None
Environment:Operating System: Microsoft Windows 10 Pro
Processor: AMD Ryzen 7 1800X Eight-Core Processor
Installed Memory (RAM): 32.0GB
Video Card: GeForce GTX 1080
Video Driver: v398.11
Minecraft Version: Java Edition v1.13-pre2
Upon starting a new game using default settings and no mods, very close to my spawn location I discovered what a appears to be a chunk entirely composed of coal just outside of a village.
I assume this is not by design.
Hope that helps!