Figuring that nobody really wants to wait a whole week for traditional rock candy to crystallize, eventually we found this easy microwave hard candy recipe, upon which we based the recipe below.
It reminded us immediately of rock candy. The in-game picture shown above depicts pale but not colorless lumps or chunks of various sizes. It's illegal in much of Tamriel: in Morrowind many shopkeepers won't even do business with you if you're carrying the stuff (not so in the more lawless land of Skyrim).
It has magical properties, can be used as an alchemy ingredient, and is a strong narcotic. Moon sugar is described as a crystal made from the canes of certain grasses in Elsweyr.
Here you can buy and sell goods many merchants in town will avoid, including the less-than-licit moon sugar. These clusters of tents are temporary trading posts set up by the nomadic Khajiiti, a feline race from the exotic desert land of Elsweyr. Wander the roads and byways of Skyrim, and eventually you're bound to run into a rough encampment by the side of the road on the way into town.