The three common core types are unicorn hair, dragon heartstring and phoenix feather. Unicorn is probably the most common and is the easiest to do magic with, though they do not have the widest range of magic. Dragon heartstring are usually more temperamental and are known for being used by those using the Dark Arts. They have a wide range of magic though. Phoenix feather is the rarest and has the widest range of magic. They sometimes make decisions on their own. These cores are picky and hard won. Other magical cores may be used but are not as common.