You know how on very fancy cakes they have those decorations that look like glass but are edible? I assume they'd taste like candy or something, but what're they called? They tend to be colored and kind of see through, a pictures of what I'm talking about is :

http://www.streetdirectory.com/stock_images/travel/simg_show/11926962850106/1/dessert_3/

the blue thing that looks kind of clear. :
Anyone know what that's called or what it's made of?