Definitions
Nearby Words

# Orthorhombic crystal system

In crystallography, the orthorhombic crystal system is one of the seven lattice point groups. Orthorhombic lattices result from stretching a cubic lattice along two of its orthogonal pairs by two different factors, resulting in a rectangular prism with a rectangular base (a by b) and height (c), such that a, b, and c are distinct. All three bases intersect at 90° angles. The three lattice vectors remain mutually orthogonal.

There are four orthorhombic Bravais lattices: simple orthorhombic, base-centered orthorhombic, body-centered orthorhombic, and face-centered orthorhombic.

 simple orthorhombic base-centeredorthorhombic body-centeredorthorhombic face-centeredorthorhombic

The point groups (or crystal classes) that fall under this crystal system are listed below, followed by their representations in International {Hermann-Mauguin) notation and Schoenflies notation, and mineral examples.

Name International Schoenflies Example
orthorhombic bipyramidal $frac2mmm$ D2h sulfur, olivine, aragonite
orthorhombic pyramidal $2 mm$ C2v hemimorphite, bertrandite
orthorhombic sphenoidal $222$ D2 epsomite