The base game puts no limitation on which civilizations can mine or forge with cotton candy. Instead it is kept from the elves simply by making elves unplayable. As such, I have given smelting reactions to the dwarves to "make of it a metal, light and yet harder than tempered steel". As such, the default condition cotton candy comes in is tremendously heavy. Only an exceptionally strong and high-endurance warrior can make use of armor in this state, although given both its sharpness and its weight, it may be perfectly suited for particular applications.