Crystal

A crystal or crystalline solid is a solid fabric whose constituents such(a) as atoms, molecules, or ions are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macroscopic single crystals are usually identifiable by their geometrical shape, consisting of flat faces with specific, characteristic orientations. The scientific explore of crystals as alive as crystal layout is invited as crystallography. The process of crystal format via mechanisms of crystal growth is called crystallization or solidification.

The word crystal derives from the rock crystal", from κρύος , "icy cold, frost".

Examples of large crystals increase snowflakes, diamonds, as well as table salt. nearly inorganic solids are not crystals but polycrystals, i.e. many microscopic crystals fused together into a single solid. Examples of polycrystals include almost metals, rocks, ceramics, together with ice. A third breed of solids is amorphous solids, where the atoms work no periodic structure whatsoever. Examples of amorphous solids include glass, wax, and many plastics.

Despite the name, lead crystal, crystal glass, and related products are not crystals, but rather brand of glass, i.e. amorphous solids.

Crystals are often used in pseudoscientific practices such(a) as crystal therapy, and, along with gemstones, are sometimes associated with spellwork in Wiccan beliefs and related religious movements.

Chemical bonds

In general, solids can be held together by various types of chemical bonds, such(a) as metallic bonds, ionic bonds, covalent bonds, van der Waals bonds, and others. None of these are necessarily crystalline or non-crystalline. However, there are some general trends as follows.

Metals are almost always polycrystalline, though there are exceptions like amorphous metal and single-crystal metals. The latter are grown synthetically. A microscopically-small ingredient of metal may naturally realise into a single crystal, but larger pieces generally do not. Ionic compound materials are commonly crystalline or polycrystalline. In practice, large salt crystals can be created by solidification of a molten fluid, or by crystallization out of a solution. Covalently bonded solids sometimes called covalent network solids are also very common, notable examples being diamond and quartz. Weak van der Waals forces also guide hold togethercrystals, such as crystalline molecular solids, as living as the interlayer bonding in graphite. Polymer materials broadly will form crystalline regions, but the lengths of the molecules usually prevent fix crystallization—and sometimes polymers are completely amorphous.