This idea started with a book I purchased some years ago, A Witch’s Book of Divination by Callia Underhill (St. Paul, Minnesota: Llewellyn Publications, 1996, pp.31-60). Ms. Underhill featured a number of divination methods in her book which I’d never heard of or seen before. One of those methods I simply had to try was called ‘Herne’s Head’.  A diagram of Herne’s Head, with a number of other symbols arranged on and around it was to be used as the casting surface for this divination method.

Each part of the picture had a ‘light’ and a ‘shadow’ meaning, and an attendant explanatory paragraph. With both the light and shadow stones in hand, the inquirer recites a short verse, then casts both stones onto the diagram. You then read the light and shadow section for each stone. This gives you both the positive and the negative side of whatever issue you were inquiring about.