The stuff the Belgian's use is carmalized. (Which is NOT the same as using caramel chunks).
That said, I dumped in a bunch of rock candy and I beleive, becasue it took longer to disolve and was sitting at the bottom where it was hot, since it was heavy, that the boil carmalized some of the sugar anyway.
There are different ways that sugar can be carmalized. One way is the type the Monks use. I have a book somewhere with all that brewing goodness explained in it, but I just moved and have no idea where it is.