The types of ice that form on aircraft structure are rime ice, clear ice, and mixed ice.
Rime ice is rough, milky, opaque ice formed by the instantaneous freezing of small super-cooled water droplets.
Clear ice is glossy, clear, or translucent ice formed by the relatively slow freezing of large, super-cooled water droplets.
Mixed ice is a combination of rime and clear ice.
FAA AC 00-6B Aviation Weather pg. 18-1