Kristallijärjestelmiin

Kristallijärjestelmiin refers to the classification of crystals based on their internal atomic structure and symmetry. There are seven fundamental crystal systems, each defined by the lengths of its crystallographic axes and the angles between them. These systems are cubic, tetragonal, orthorhombic, monoclinic, triclinic, hexagonal, and trigonal.

The cubic system is the most symmetrical, with all three axes of equal length and perpendicular to each other. Examples include salt and diamond. The tetragonal system has three equal axes, but only two are perpendicular. The orthorhombic system has three unequal axes that are all mutually perpendicular.

In the monoclinic system, the three axes are unequal, and only two are perpendicular. The triclinic system is the least symmetrical, with all three axes unequal and no perpendicular angles. The hexagonal system has four axes, three of equal length in a plane at 120-degree angles, and a fourth axis perpendicular to this plane. The trigonal system, sometimes considered a subdivision of the hexagonal system, is characterized by three equal axes at 120-degree angles in a plane.

The specific kristallijärjestelmä of a mineral or material dictates many of its physical properties, such as its cleavage, hardness, and optical characteristics. Understanding these systems is crucial in mineralogy, crystallography, and materials science.