Quartz crystal

A crystal is a solid in which the constituent atoms, molecules, or ions are packed in a regularly ordered, repeating pattern extending in all three spatial dimensions. Commons:Image:Quartz Crystal. ... Commons:Image:Quartz Crystal. ... Quartz is the most abundant mineral in the Earths continental crust. ... In jewelry, a solid gold piece is the alternative to gold-filled or gold-plated jewelry. ... Properties An atom (Greek άτομον from ά: non and τομον: divisible) is a submicroscopic structure found in all ordinary matter. ... A molecule is the smallest particle of a pure chemical substance that still retains its chemical composition and properties. ... An ion is an atom or group of atoms with a net electric charge. ...

Generally, fluid substances form crystals when they undergo a process of solidification. Under ideal conditions, the result may be a single crystal, where all of the atoms in the solid fit into the same lattice or crystal structure but, generally, many crystals form simultaneously during solidification, leading to a polycrystalline solid. For example, most metals encountered in everyday life are polycrystals. Crystals are often symmetrically intergrown to form crystal twins. A subset of the phases of matter, fluids include liquids, gases, plasmas and, to some extent, plastic solids. ... A single crystal is a crystalline solid in which the crystal lattice of the entire sample is continuous and unbroken to the edges of the sample. ... The ordinary meaning of lattice is the basis for several technical usages A cherry lattice pastry A mathematical lattice that is a type of partially ordered set. ... Rose des Sables (Sand Rose), formed of gypsum crystals In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. ... For alternative meanings see metal (disambiguation). ... A twin boundary occurs when two crystals of the same type intergrow, so that only a slight misorientation exists between them. ...

Which crystal structure the fluid will form depends on the chemistry of the fluid, the conditions under which it is being solidified, and also on the ambient pressure. The process of forming a crystalline structure is often referred to as crystallization. Rose des Sables (Sand Rose), formed of gypsum crystals In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. ... Pressure (symbol: p) is the force per unit area acting on a surface in a direction perpendicular to that surface. ...

Bismuth Crystal

While the process of cooling usually results in the generation of a crystalline material, under certain conditions the fluid may be frozen in a noncrystalline state. In most cases, this involves cooling the fluid so rapidly that atoms cannot travel to their lattice sites before they lose mobility. A noncrystalline material, which has no long-range order, is called an amorphous, vitreous, or glassy material. It is also often referred to as an amorphous solid, although there are distinct differences between solids and glasses: most notably, the process of forming a glass does not release the latent heat of fusion. For this reason, many scientists consider glassy materials to be viscous liquids rather than solids, although this is a controversial topic; see the entry on glass for more details. Bismuth Crystal Photograph taken by Intangir. ... Bismuth Crystal Photograph taken by Intangir. ... General Name, Symbol, Number bismuth, Bi, 83 Chemical series poor metals Group, Period, Block 15, 6, p Appearance lustrous reddish white Atomic mass 208. ... In physics, long-range order characterizes physical systems in which remote portions of the same sample exhibit correlated behavior. ... Vitreous refers to a material in a glassy state. ... For eyeglasses, see glasses. ... An amorphous solid is a solid in which there is no long-range order of the positions of the atoms. ... The latent heat of fusion of a substance is the amount of energy per unit mass required to turn a specified amount of the substance in its solid phase at its melting point to a liquid at the same temperature. ... The pitch drop experiment at the University of Queensland. ... For eyeglasses, see glasses. ...

Insulin crystals

Crystalline structures occur in all classes of materials, with all types of chemical bonds. Almost all metal exists in a polycrystalline state; amorphous or single-crystal metals must be produced synthetically, often with great difficulty. Ionically bonded crystals can form upon solidification of salts, either from a molten fluid or when it condenses from a solution. Covalently bonded crystals are also very common, notable examples being diamond, silica, and graphite. Polymer materials generally will form crystalline regions, but the lengths of the molecules usually prevents complete crystallization. Weak Van der Waals forces can also play a role in a crystal structure; for example, this type of bonding loosely holds together the hexagonal-patterned sheets in graphite. Commons:Image:Insulincrystals. ... Commons:Image:Insulincrystals. ... The structure of insulin Red: carbon; green: oxygen; blue: nitrogen; pink: sulfur. ... A chemical bond is the phenomenon of atoms being held together in molecules, crystals or in solid metal. ... Metallic bonding is the bonding within metals. ... Electron configurations of lithium and fluorine. ... Covalent bonding is a form of chemical bonding characterized by the sharing of one or more pairs of electrons between atoms, in order to produce a mutual attraction, which holds the resultant molecule together. ... Polymer is a generic term used to describe a very long molecule consisting of structural units and repeating units connected by covalent chemical bonds. ... In chemistry, the term Van der Waals force originally referred to all forms of intermolecular forces; however, in modern usage it tends to refer to intermolecular forces that deal with forces due to the polarization of molecules. ... Graphite (named by Abraham Gottlob Werner in 1789, from the Greek γραφειν: to draw/write, for its use in pencils) is one of the allotropes of carbon. ...

Most crystalline materials have a variety of crystallographic defects. The types and structures of these defects can have a profound effect on the properties of the materials. Crystalline solids have a very regular atomic structure: that is, the local positions of atoms with respect to each other are repeated at the atomic scale. ...

Gallium, a metal that easily forms large single crystals

A large artificial monocrystal grown by Saint-Gobain for the megajoule laser of CEA.

While the term "crystal" has a precise meaning within materials science and solid-state physics, colloquially "crystal" refers to solid objects that exhibit well-defined and often pleasing geometric shapes. Various shapes of such crystals are found in nature. The shape of these crystals is dependent on the types of molecular bonds between the atoms to determine the structure, as well as on the conditions under which they formed. Snowflakes, diamonds, and common salt are common examples of crystals. Crystals of 99. ... Crystals of 99. ... General Name, Symbol, Number gallium, Ga, 31 Chemical series poor metals Group, Period, Block 13, 4, p Appearance silvery white   Atomic mass 69. ... Download high resolution version (2232x1700, 1446 KB) Wikipedia does not have an article with this exact name. ... Download high resolution version (2232x1700, 1446 KB) Wikipedia does not have an article with this exact name. ... Saint-Gobain is a multinational corporation, founded and headquartered in France. ... The Commissariat à lÉnergie Atomique or CEA, the Atomic Energy Commisson, in English, is a French public establishment of an industrial and commercial character whose mission is to develop all applications of atomic energy, both civilian and military. ... The Materials Science Tetrahedron, which often also includes Characterization at the center Materials science is the multidisciplinary field relating the performance and function of matter in any and all applications to its micro, nano, and atomic-structure, and vice versa. ... Solid-state physics, the largest branch of condensed matter physics, is the study of rigid matter, or solids. ... Snow crystal A snowflake is an aggregate of snow crystals that form while falling in and below a cloud. ... A scattering of round-brilliant cut diamonds shows off the many reflecting facets. ... In chemistry, salt is a term used for ionic compounds composed of positively charged cations and negatively charged anions, so that the product is neutral and without a net charge. ...

Some crystalline materials may exhibit special electrical properties such as the ferroelectric effect or the piezoelectric effect. In physics, the ferroelectric effect is an electrical phenomenon whereby certain ionic crystals may exhibit a spontaneous dipole moment. ... Piezoelectricity is the ability of certain crystals to generate a voltage in response to applied mechanical stress. ...

The behaviour of light in crystals is described by crystal optics. In periodic dielectric structures a range of unique optical properties can be expected as described in photonic crystals. Prism splitting light Light is electromagnetic radiation with a wavelength that is visible to the eye (visible light) or, in a technical or scientific setting, electromagnetic radiation of any wavelength. ... Crystal optics is the branch of optics that describes the behaviour of light in anisotropic media, that is, media (such as crystals) in which light behaves differently depending on which direction the light is propagating. ... The electrons in the molecules shift toward the positively charged left plate. ... The opal in this bracelet contains a natural periodic microstructure responsible for its iridescent color. ...

Crystallography is the scientific study of crystals and crystal formation. Crystallography (from the Greek words crystallon = cold drop / frozen drop, with its meaning extending to all solids with some degree of transparency, and graphein = write) is the experimental science of determining the arrangement of atoms in solids. ...

See also

• Crystal habit
• Crystal structure
• Crystallite
• Crystallization processes
• Liquid crystal
• Quasicrystal
• Seed crystal
• Single crystal

In mineralogy, shape and size give rise to descriptive terms applied to the typical appearance, or habit of crystals. ... Rose des Sables (Sand Rose), formed of gypsum crystals In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. ... A crystallite is a domain of solid-state matter that has the same structure as a single crystal. ... Crystallization is essentially a solid-liquid separation technique. ... Schlieren texture of Liquid Crystal nematic phase Liquid crystals are substances that exhibit a phase of matter that has properties between those of a conventional liquid, and those of a solid crystal. ... Quasicrystals are a peculiar form of solid in which the atoms of the solid are arranged in a seemingly regular, yet non-repeating structure. ... A seed crystal is a small piece of single crystal material from which a large crystal of, usually, the same material is to be grown. ... A single crystal is a crystalline solid in which the crystal lattice of the entire sample is continuous and unbroken to the edges of the sample. ...

External links

• Introduction to Crystallography and Mineral Crystal Systems
• Crystallographic Teaching Pamphlets
• Crystal Lattice Structures