Can overcooked caramel be harmful? Ok, here's the situation. I put a pan of water and sugar on a medium high flame and went away. Some time later I found a smoldering black mass overflowing the pan. It took some time to clean up (anybody know how to remove burnt caramel from stainless steel?).

I threw the burnt caramel away, but later started wondering. There is a sweet called 'carbon' and I have no idea how it's made, but it looks the same as what was in the pan... So there's the question. How is 'carbon' made? 

Edit The question was whether the burnt sugar is edible. The answer of course is: no.
I think what your looking for is called poured sugar oil moulds(rings) that you want to use ant shape is okay then use 2 lbs sugar,1 lb water, 6.55 ounces of glucose  and food colouring if you want.make a syrup with the three and then boil until it reaches 260F add food colouring continue to boil until temp. reaches 330F  plunge the pot into a cold water bath to stop the cooking.remove from water and let stand 2-3 minutes to thicken. Pour mixture into moulds until 1/4 inch thick. Once edges have setenough remove the ring. Use a little reheated sugar to attached pieces together like a glue.this can be used as a base for any center piece you want to create with other sugar pieces