A crystal is a solid formed by the solidification of chemicals, has a regularly repeating internal arrangement of atoms and molecules, and is bounded by external plane faces. Crystal particles form a variety of geometrical shapes due to their internal compressions. Crystals have aesthetic properties that have long made them attractive in jewelry. But they also have some properties that make them very important to the electronics and optical industries. Today, crystals are used in just about every type of modern technology.
For centuries, crystals and other gems have been desired for their alleged magical healing and mystical paranormal powers. This belief continues today among occultists and New Age healers, even though it is based on nothing more than testimonials, the placebo effect, selective thinking, wishful thinking, the Forer effect, sympathetic magic, and communal reinforcement. There is no scientific evidence that crystals are conduits of magical energies useful for healing and protection, or for telling the future.