What is crystal

Crystals can be observed in various aspects of everyday life, including natural and artificial contexts:

Natural Crystals:

  • Snowflakes: These are beautiful examples of natural ice crystals with a distinct geometric structure.

  • Gemstones: Many gemstones, such as diamonds and quartz, are crystalline in nature and exhibit well-defined crystal faces and structures.

  • Salt and Sugar: Both salt and sugar crystals are commonly observed in everyday life, especially when examined under a microscope.

  • Artificial Crystals: Laboratory-grown Crystals: Crystals can be artificially created in laboratory settings for various applications, such as in electronics and optics.

However, the crystal structure in terms of atomic arrangement plays a much larger role in our lives. Crystals are found in a variety of materials, including:

  • All metals: Most metals in the ground state at normal conditions have a crystalline structure, with their atoms arranged in a regular and repeating pattern.

  • Ionic Compounds: Substances like table salt (sodium chloride) and many other ionic compounds form crystals due to the arrangement of positive and negative ions in a regular pattern.

  • Covalent Compounds: Materials such as diamonds, which are made up of carbon atoms, also have a crystalline structure.

  • Other Substances: Additionally, materials like ice, sugar, and some polymers exhibit crystalline structures to varying degrees.

A crystal or crystalline solid is a solid-phase 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. Crystals are characterized by their regular arrangement of atoms or ions, which results in a well-defined internal structure and often a specific geometrical shape with flat faces. The scientific study of crystals and crystal formation is known as crystallography.

Crystals can be classified into different categories, such as insulators, metals, semiconductors, and molecular solids. They can also be classified based on their crystal systems, which include tetragonal, orthorhombic, monoclinic, triclinic, hexagonal, and trigonal systems.

Crystals can have natural origins, forming through inorganic or organic processes, or they can be artificially created in laboratories.

Examples of crystals include snowflakes, diamonds, metals and alloys or ceramic materials. Some crystals, like quartz, silicon, are used in various applications, such as in electronics.

DOI: 10.5772/37157

Image from DOI: 10.5772/37157