Releasing a sigh, I explained some history. "Seeing the confusion on your face, let me explain. The Astral plane is where all magic comes from. It is through certain rituals and other means, like our magical cores, that bring magic into the Material plane. The crystals could have been created from pockets through the barrier, becoming physical material. But they are not a direct connection to the Astral plane. The leylines on the other hand, do. They have been on the isles far longer than written history, at least what I can tell."