are solid materials with complex constitutions that have a highly ordered microscopic structure. Examples of large crystals include snowflakes, diamonds, and table salt. The scientific study of crystals and crystal formation is known as crystallography, and is the experimental science of determining the arrangement of atoms in the crystalline solids. The word "crystallography" derives from the Greek words crystallon "cold drop, frozen drop", with its meaning extending to all solids with some degree of transparency, and grapho "I write".
Crystal's symmetry is constrained by the requirement that the unit cells stack perfectly with no gaps. There are almost 220 possible crystal symmetries, called crystallographic space groups. These are grouped into 7 crystal systems, such as cubic crystal system (where the crystals may form cubes or rectangular boxes, such as halite shown at right) or hexagonal crystal system (where the crystals may form hexagons, such as ordinary water ice). Some crystals have formed by magmatic and metamorphic processes, giving origin to large masses of crystalline rock. The vast majority of igneous rocks are formed from molten magma and the degree of crystallization depends primarily on the conditions under which they solidified. Water-based ice in the form of snow, sea ice and glaciers is a very common manifestation of crystalline or polycrystalline matter on Earth. A single snowflake is typically a single crystal, while an ice cube is a polycrystal.
The use of Crystals in Health
We are a very complex specie in the world, and therefore we tend to suffer a major number of problems related to the inner body, mind and soul. Crystals have been around humanity since many millenniums, and they have been known to be great for easing worries, solving problems and reviving harmony in life. They also have been very well known for aiding to deal with abandonment, depression, anxiety, and self-acceptance.