It's a hollow 3x3x3 obsidian block (engraving optional) made to contain anything game-crashing; as well as when teleportation eventually becomes a DFHack reality, eternal prison for any creature you never want wandering at all, and want to contain them until they die off. Heads-up, upon reclaim, inside will be dark, and undiscovered. Reveal may be needed if this is the case; unless you don't need to see where you place things with Autodump).
I call it
Project: Black-Box.
(Named after those nigh-indestructible recorders in aircraft and other transportation that hold sensitive info on crashes. And it's also a pun on the obsidian artifact.)
Alternative name:
Project: Pandora's Box.
(Because you don't want the stuff inside to be let out (evil contained); and when it's empty, all that's left is Hope. Hope that the game won't crash when the items are in use again.)
It's immune to all outside forces (especially thieves (even flying ones) and magma that can damage or destroy the "sacred" game crashing objects in question), besides a dwarf's mining pick (Or using Liquids to replace an obsidian wall with a floor to get inside (if you want to engrave inside and out; like I did in the image; every obsidian tile, including the unseen center walls, are engraved)). Besides all that, the items within are Autodump-ed (DFHack command) into the interior of the hollow artifact. Announcements and gamelog.txt help me identify the problem items to seal for eternity whenever they come up. So far, the device works as intended, and I recommend it for anyone else suffering such bugs.
I engraved "warnings" all over it to make it more ominous looking in-game and in Stonesense, and any other visualizer. Fortunately, none of the engravings are masterwork, so my engraver won't go into a blind rage in case I melt off the markings when I dump magma on or near it.
I suggest you bury this deep underground, or in Hell, even, if possible; Or at least somewhere you will never access, or never intend to mine out or work on. Or in my case, a spot where it's aesthetically pleasing, yet easy to access, in case of repeat incidents. Plus, this is a proof-of-concept for me, so I'm closely monitoring it as I play; making sure nothing, somehow, teleports outside of it.