Blocks of Quantum (or Quantum Blocks) are valuable items nessisary to the build configuration of Quantum Withers. It has other neat uses that make it stand out from a crowd. It is crafted by putting Quantum in every crafting slot, which yields two BOQ instead of the regular one, like other blocks of precious minerals.
Blocks of Quantum can produce their own light (light level of 12) and, when placed, can be toggled on or off to either generate a large field that slows/quickens time, teleports anything but the player to a random location when it enters the field, or to generate an anti-gravity field. This is all changed by hitting the F key for turning these on or off, and the V key for switching between various effects.