Monoklinic

Monoklinic is a crystal system characterized by three crystallographic axes of unequal length that are inclined to each other at two right angles and one oblique angle. This means that in the monoklinic system, the unit cell has three axes of different lengths, denoted as a, b, and c, where a ≠ b ≠ c. The angles between these axes are also not all 90 degrees. Specifically, two of the angles are right angles (90 degrees), and the third angle is oblique (not 90 degrees). These angles are typically represented as α, β, and γ. In the monoklinic system, we have α = γ = 90° and β ≠ 90°.

The symmetry elements present in the monoklinic system are limited. It can possess a single twofold rotation axis or a single mirror plane, or both. It cannot have a center of symmetry. This restricted symmetry leads to fewer possible point groups compared to higher crystal systems. The seven crystal classes within the monoklinic system are: 2, m, 2/m, 222, mm2, 2mm, and 2/m2/m2/m. However, the most common and representative classes are 2, m, and 2/m.

Minerals crystallizing in the monoklinic system include important examples such as gypsum, orthoclase feldspar, and augite. These minerals exhibit varying physical properties depending on their specific chemical composition and atomic arrangement, but their overall crystallographic framework adheres to the monoklinic parameters. The study of monoklinic crystals is crucial in mineralogy, crystallography, and materials science for understanding the properties and formation of these materials.