John Dee's Obsidian Crystal Ball

Origin
John Dee was an astronomer, mathematician, occultist and royal advisor to Queen Elizabeth I. He spent much of his life devoted to the study of alchemy, divination and other occult arts. Dee taught advanced algebra and helped teach navigation to many of the British explorers entering the New World. At the same time, Dee dabbled in magic, astrology and Hermeticism. Later in life, he worked with fellow occultist Edward Kelley to try and find the universal language of angels. Both Dee’s scientific and magical ventures were in pursuit of communication with angelic beings.

Dee possessed one of the largest libraries in England at the time and played a large role in Elizabethan politics. He was the royal scientific and astrological advisor to Queen Elizabeth, choosing her coronation date himself.

The crystal ball was used to foretell the Spanish Armada's arrival and tell Elizabeth of their approach to shore.

Effects
When rubbed and a person, group or future date is thought of, it shows what that person does or what events happen on said date. It can be narrowed down to a specific detail or widened to all events on a global scale. Those in power, whether business or governmental, will become susceptible to the user’s suggestions about the future, whether they are true or lies.