How to craft it
Work BenchUsed to craft
mining it without losing half the vein
The blocks crumble into each other. Breaking one can take its neighbors with it, and the odds are much worse for any block with nothing underneath, so the moment you open a hole the collapse starts spreading downward on its own. Digging a vein from the bottom up is the fastest way to destroy most of it.
Work in flat horizontal passes from the top down and keep the face solid, with nothing left hanging over an air gap. Explosives are the other answer, and scarab bombs in particular clear a wide chunk at once while still collecting what they break.
why you want it
The reason to haul it home is the extractinator, which turns it into sturdy fossils and, along the way, into ordinary ores and gems. Amber comes out of this material more often than out of slush or silt, so if amber is what you are chasing, this is what to feed the machine.
A spelunker potion highlights it, which saves a lot of aimless wandering through an underground desert.