triklinism

Triklinism is a term sometimes used in geology, particularly in the context of crystal structures. It refers to a crystallographic system where a crystal's unit cell has three axes of unequal length, and the angles between these axes are also unequal, but none of them are necessarily 90 degrees. This description precisely defines the triclinic crystal system. Crystals in the triclinic system exhibit the lowest symmetry of all crystal systems. Their unit cells are characterized by parameters a ≠ b ≠ c and α ≠ β ≠ γ, where none of the angles are right angles. Examples of minerals that crystallize in the triclinic system include plagioclase feldspar, kyanite, and turquoise. The lack of symmetry in triklinism means that there are no planes of symmetry or axes of rotation within the crystal structure, making them the most complex to describe and analyze from a crystallographic perspective. The term itself is derived from Greek words meaning "three" and "to recline," reflecting the arrangement of the axes.