Monoclínica

Monoclínica is the Spanish term used in crystallography and mineralogy to refer to the monoclinic crystal system. It describes crystals that crystallize within this lattice type and, more broadly, any substance whose crystalline form belongs to the monoclinic class.

In the monoclinic system, the unit cell is defined by three axes of unequal length, where two axes are perpendicular to each other and the third is inclined. In standard settings, the lattice parameters satisfy a ≠ b ≠ c, with α = γ = 90° and β ≠ 90°. This arrangement yields a characteristic symmetry that is less than orthorhombic but more than triclinic, allowing several symmetry elements and giving rise to the common monoclinic point groups 2, m, and 2/m.

Monoclínica crystals can exhibit a variety of habits, often prismatic or tabular, and their external forms reflect the underlying symmetry of the monoclinic lattice. Minerals that crystallize in the monoclinic system include gypsum, many micas (such as muscovite and biotite), orthoclase, and other feldspars and sulfates. The term is routinely used in Spanish-language geology and mineralogy literature to distinguish monoclinic crystals from those in other crystal systems.

Relation to other terms: monoclínica is an adjective describing this crystal system; the corresponding noun phrase is usually "sistema monoclinico" or "cristales monoclinos." It is one of seven crystal systems used to classify crystalline materials based on lattice geometry and symmetry.