Typically needs to be magically-infused calcite chalk for that traditional feeling that your new demon friend will appreciate and respect you for. If you can’t infuse the chalk yourself, store bought is fine but you might end up with unexpected results based on the source.
As a note for Jerboa users: the above link may instantly crash the app. At least, it does for me.
I hate to tell you this, but the previous one was, too.