Crystal

crystallinecrystalscrystalline solidcrystalline rockcrystalline solidscrystalline materialcrystal formcrystalline rocksatomic latticecrystal faces
A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions.wikipedia
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Solid

solidsssolid state
A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions.
The atoms in a solid are tightly bound to each other, either in a regular geometric lattice (crystalline solids, which include metals and ordinary ice) or irregularly (an amorphous solid such as common window glass), and are typically low in energy.

Crystallization

crystallizecrystallisationcrystallized
The process of crystal formation via mechanisms of crystal growth is called crystallization or solidification.
Crystallization or crystallisation is the (natural or artificial) process by which a solid forms, where the atoms or molecules are highly organized into a structure known as a crystal.

Crystal growth

growngrowthcrystal growing
The process of crystal formation via mechanisms of crystal growth is called crystallization or solidification.
Crystal growth, is the process where a pre-existing crystal becomes larger as more molecules or ions add in their positions in the crystal lattice or a solution is developed into a crystal and further growth is processed.

Atom

atomsatomic structureatomic
A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions.
Atoms can attach to one or more other atoms by chemical bonds to form chemical compounds such as molecules or crystals.

Crystallography

crystallographercrystallographiccrystallographically
The scientific study of crystals and crystal formation is known as crystallography.
Before the development of X-ray diffraction crystallography (see below), the study of crystals was based on physical measurements of their geometry.

Bravais lattice

crystal latticelatticeBravais lattices
A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions.
A crystal is made up of a periodic arrangement of one or more atoms (the basis, or motif) repeated at each lattice point.

Ion

cationanionions
A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions.
Cations and anions are measured by their ionic radius and they differ in relative size: "Cations are small, most of them less than 10 −10 m (10 −8 cm) in radius. But most anions are large, as is the most common Earth anion, oxygen. From this fact it is apparent that most of the space of a crystal is occupied by the anion and that the cations fit into the spaces between them."

Ice

water iceicyglacier ice
The word crystal derives from the Ancient Greek word κρύσταλλος, meaning both "ice" and "rock crystal", from κρύος, "icy cold, frost". Most macroscopic inorganic solids are polycrystalline, including almost all metals, ceramics, ice, rocks, etc. Solids that are neither crystalline nor polycrystalline, such as glass, are called amorphous solids, also called glassy, vitreous, or noncrystalline. Examples of polycrystals include most metals, rocks, ceramics, and ice.
It possesses a regular crystalline structure based on the molecule of water, which consists of a single oxygen atom covalently bonded to two hydrogen atoms, or H–O–H.

Freezing

solidificationfrozenfreeze
The process of crystal formation via mechanisms of crystal growth is called crystallization or solidification.
Most liquids freeze by crystallization, formation of crystalline solid from the uniform liquid.

Gemstone

gemgemsgemstones
Crystals are often used in pseudoscientific practices such as crystal therapy, and, along with gemstones, are sometimes associated with spellwork in Wiccan beliefs and related religious movements.
A gemstone (also called a gem, fine gem, jewel, precious stone, or semi-precious stone) is a piece of mineral crystal which, in cut and polished form, is used to make jewelry or other adornments.

Quasicrystal

quasicrystalsquasi-crystalquasicrystalline
(Quasicrystals are an exception, see below).
A quasiperiodic crystal, or quasicrystal, is a structure that is ordered but not periodic.

Crystallite

polycrystallinegraingrains
Most inorganic solids are not crystals but polycrystals, i.e. many microscopic crystals fused together into a single solid. In the final block of ice, each of the small crystals (called "crystallites" or "grains") is a true crystal with a periodic arrangement of atoms, but the whole polycrystal does not have a periodic arrangement of atoms, because the periodic pattern is broken at the grain boundaries.
A crystallite is a small or even microscopic crystal which forms, for example, during the cooling of many materials.

Crystal structure

unit celllatticecrystal lattice
The scientific definition of a "crystal" is based on the microscopic arrangement of atoms inside it, called the crystal structure. The flat faces (also called facets) of a euhedral crystal are oriented in a specific way relative to the underlying atomic arrangement of the crystal: they are planes of relatively low Miller index.
In crystallography, crystal structure is a description of the ordered arrangement of atoms, ions or molecules in a crystalline material.

Grain boundary

grain boundaries grain boundariescrystallite discontinuities
In the final block of ice, each of the small crystals (called "crystallites" or "grains") is a true crystal with a periodic arrangement of atoms, but the whole polycrystal does not have a periodic arrangement of atoms, because the periodic pattern is broken at the grain boundaries.
Grain boundaries are 2D defects in the crystal structure, and tend to decrease the electrical and thermal conductivity of the material.

Amorphous solid

amorphousamorphous solidsamorphous materials
A third category of solids is amorphous solids, where the atoms have no periodic structure whatsoever. Most macroscopic inorganic solids are polycrystalline, including almost all metals, ceramics, ice, rocks, etc. Solids that are neither crystalline nor polycrystalline, such as glass, are called amorphous solids, also called glassy, vitreous, or noncrystalline.
In condensed matter physics and materials science, an amorphous (from the Greek a, without, morphé, shape, form) or non-crystalline solid is a solid that lacks the long-range order that is characteristic of a crystal.

Plastic

plasticsadditivesadditive
Examples of amorphous solids include glass, wax, and many plastics.
However, some plastics are partially crystalline and partially amorphous in molecular structure, giving them both a melting point, the temperature at which the attractive intermolecular forces are overcome, and also one or more glass transitions, the temperatures above which the extent of localized molecular flexibility is substantially increased.

Cubic crystal system

cubicisometricface-centered cubic
These are grouped into 7 crystal systems, such as cubic crystal system (where the crystals may form cubes or rectangular boxes, such as Halite (mineral) shown at right) or hexagonal crystal system (where the crystals may form hexagons, such as ordinary water ice).
This is one of the most common and simplest shapes found in crystals and minerals.

Euhedral and anhedral

euhedralanhedralsubhedral
Euhedral crystals are those with obvious, well-formed flat faces. The flat faces (also called facets) of a euhedral crystal are oriented in a specific way relative to the underlying atomic arrangement of the crystal: they are planes of relatively low Miller index.
Euhedral crystals (also known as idiomorphic or automorphic crystals) are those that are well-formed, with sharp, easily recognised faces.

Crystal habit

habitMassivetabular
A crystal's habit is its visible external shape.
In mineralogy, crystal habit is the characteristic external shape of an individual crystal or crystal group.

Crystal system

systemlattice systemcrystallographic point 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 (mineral) shown at right) or hexagonal crystal system (where the crystals may form hexagons, such as ordinary water ice).
In crystallography, the terms crystal system, crystal family, and lattice system each refer to one of several classes of space groups, lattices, point groups, or crystals.

Facet

crystal facetsfacetedfaceting
The flat faces (also called facets) of a euhedral crystal are oriented in a specific way relative to the underlying atomic arrangement of the crystal: they are planes of relatively low Miller index.
The organization of naturally occurring facets was key to early developments in crystallography, since they reflect the underlying symmetry of the crystal structure.

Rock (geology)

stonerockrocks
Most macroscopic inorganic solids are polycrystalline, including almost all metals, ceramics, ice, rocks, etc. Solids that are neither crystalline nor polycrystalline, such as glass, are called amorphous solids, also called glassy, vitreous, or noncrystalline.
This material forms crystals with other compounds in the rock.

Metal

metalsmetal ionsmetal ion
Most macroscopic inorganic solids are polycrystalline, including almost all metals, ceramics, ice, rocks, etc. Solids that are neither crystalline nor polycrystalline, such as glass, are called amorphous solids, also called glassy, vitreous, or noncrystalline. Examples of polycrystals include most metals, rocks, ceramics, and ice.
A temperature change may affect the movement or displacement of structural defects in the metal such as grain boundaries, point vacancies, line and screw dislocations, stacking faults and twins in both crystalline and non-crystalline metals.

Beryl

aquamarinemorganitered beryl
, the world's largest known naturally occurring crystal is a crystal of beryl from Malakialina, Madagascar, 18 m long and 3.5 m in diameter, and weighing 380,000 kg.
Naturally occurring, hexagonal crystals of beryl can be up to several meters in size, but terminated crystals are relatively rare.

Ceramic

ceramicsceramic materialsceramicist
Most macroscopic inorganic solids are polycrystalline, including almost all metals, ceramics, ice, rocks, etc. Solids that are neither crystalline nor polycrystalline, such as glass, are called amorphous solids, also called glassy, vitreous, or noncrystalline. Examples of polycrystals include most metals, rocks, ceramics, and ice.
Ceramic materials are usually ionic or covalent bonded materials, and can be crystalline or amorphous.