1. A sphere made of a crystal, typically quartz. The fewer occlusions and imperfections it has increases its value. Often used as a focal point for concentration with a purpose of divination.
2. A round ball of quartz crystal or glass used as focal point in skrying. Gazing at the ball, one enters into a trance-like state where dream like scenes and symbols are seen and interpreted. Similar aids are the Magic Mirror, a pool of black ink, a piece of obsidian.