How to Mine in the Deep Underground Below Y=0

Reaching Negative Coordinates

With the bottom of the world lowered all the way down to -64, digging to the bottom takes much longer than in a standard world. Press F3 to open your debug screen and watch your Y-coordinate as you dig downward. Once you pass zero height, normal stone is replaced by dark Deepslate blocks. Because massive underground caverns generate at these depths, never dig straight down beneath your feet. Carve a staircase or place ladders along a two-block shaft so you do not plummet through the ceiling of a giant cave.

Mining Deepslate Ores

Below Y-coordinate zero, all normal ores generate as Deepslate versions that blend into the surrounding dark stone. Bring extra stacks of torches on deep mining trips, since spotting dark-bordered ore veins across huge cavern walls is difficult in dim light. Pack spare building blocks, a water bucket, and plenty of food before descending; bridging across wide chasms and climbing all the way back up from -64 drains tools and supplies much faster than shallow surface caving.