Identification? - Extremely Odd Blue Chunk of Beach Glass
I found this piece on Roanoke Island in July of 2010, very near a bridge. The shore was thick with glass (mostly un-smooth), but I found this chunk.
I haven't been collecting and searching for more than two years, so I was really excited! It's just a really strange piece.
The whole piece is very lumpy and chunky, and just a little smooth while not being see-through. It is dark blue, cobalt.
From the sides, which are the clearest part, the inside seems to have air bubbles. There are places where it looks like sea-creatures (like barnacles?) had attached themselves, and left sandy residue.
All through it are holes that appear natural, like how a worm bores through a sea shell.
The bottom is absolutely, perfectly flat, with little ridges (think of the marks on skin after laying on grass for too long)
If I shake it, a soft black substance comes out, like charcoal and sand.
I'm completely flabbergasted by this; I haven't seen anything like it before. I apologize for the low quality of the pictures, it was the best I could do with my laptop. My best guess is that it was broken from an old appliance or light, but again, I don't know much about sea-glass yet. Please give me any ideas or suggestions (or a sure answer!) about what this is? Thank you!