Weird Object
In the Void, there are random patches of "deathly dark" rocks, which shouldn't have able to been seen, as the Void is pitch black. From what nearby harmless inhabitants speak, those rocks are called 'Grountis'. The only closely translatable word in Eques, is 'Void-Stones'. They say if any-creature native from 'Quoan' (the term inhabitants here uses to refer to the realm Equestria is in), comes in contact with the stones, the stones leaches any and all types of magical-energy from the creature. Large patches like these are apparently quite uncommon as well.
They also speak of two other types of rocks, 'Grountus', 'void-Stones', and 'Grountas', 'VOID-Stones'. 'void Stones' are the fundamental construction of the Void. These while not anything impressive here, in 'Quoan', they are magical "Replacers". It's not exactly known what that means, but guesses and tests concluded if used by a unicorn powerful enough, and great control can 'rip' cutie-marks off of ponies. HOWEVER, tests on ponies without cuties-marks kills the pony in question.
Now, 'VOID Stones'... they don't grow here, they are 'produced', and only one creature Can 'produce' them. It is said that they are made of an equilibrium amount of 'Antimatter', and 'Dark-matter'. We can only guess what destruction they can bring.