In physics, the term "crystal" describes a solid substance with internal symmetry and a related, regular surface pattern. This configuration, called the crystal structure, recurs so regularly that you can use it to predict the organization of atoms throughout the crystal. If this arrangement carries on beyond a few neighboring atoms it is called long-range order, akin to a half-time band marching in formation. Liquid crystals, like those found in LCD monitors, usually fall into short-range order (picture the marching band scatter-drilling into smaller subunits). Solid crystals can assume either pattern. Here's how: As crystalline substances melt, they become amorphous, meaning they display only short-range order. As they cool, they can either fall back into a long-rage formation or remain amorphous, like silicon-based glass.
Cast in the role of our band members are ions (positively or negatively charged atoms) linked up by ionic or covalent bonds. These bonds pack up into various compact, stable shapes called coordination polyhedra. To better picture these coordination polyhedra, forget the marching band and instead picture a geometric mosaic like those found in the Alhambra. Now visualize that mosaic in three dimensions so that its tesserae (tiles) consist of cubes, pyramids and diamond-shaped solids, each of which describes the arrangement of the atoms in a given type of crystal. Continue reading from HowStuffWorks
Historically speaking, crystals are touted as ancient forms of medicine, with philosophies borrowed from Hinduism and Buddhism. However, it’s important to know that there’s no scientific evidence to support the use of crystals. Despite this, people are still drawn to their colors and beauty. The key to indulging in this self-care experience is mindfulness, reflection, and acceptance. For instance, researchers found that a person’s mind may have much more healing power than it’s given credit. Continue reading from Healthline
