I've found two so far now, these things seem to act like danger rooms and reward you with 5 glyphs at the end!
Some pictures..
Clockwork Tunnels:
http://imgur.com/NIzfN0e
http://imgur.com/XJsWdsu
http://imgur.com/b9NYBYf
Devlish Drudgery:
http://imgur.com/J6xNmaH
http://imgur.com/JZ01LVv
I found one on the clockwork tunnels too. I died very fast :P
There is also another variant of the devilish drudgery room that I've seen. Unfortunately, I don't have a screenshot of it for you. What I remember about it, though, is that there is a hole in the middle of the room, circled by a few torto symbols and a party button.
I got one of these to reward only 1 Glyph.
Blastcore, what stratum were you in? I had done one of these rooms in stratum one and it only awarded one glyph.
Or we're just unlucky.
I'm curious as well. Even in stratum 1, I was seeing a payout of 5 glyphs per room. If ya mean one type of glyph, then that is another story.
-edit- is there any chance difficulty has any influence? I was running on elite.
Materials can sometimes "fuse" with other Materials. Did you see only one Material listed on the Chat? I've defeated a few Fiends, & they sometimes drop 1 Mat when really the other Mats dropped in the same spot.
Wow I never saw those before, that is interesting :D