No. Different people use different kinds of foci. Perhaps I am not explaining it very well.

[ He ducks his head, considering the crystal in his hand. His own focus, the other crystal around his neck, weighs heavily on his mind. ]

I'd like that. It might be easier in person, anyway; I can show you what I mean.

Do your people ever use anything other than a wand? And are all your magic users wizards, or do you have clerics and suchlike, too?