In crystallography, the orthorhombic crystal system is one of the 7 lattice point groups. Orthorhombic lattices result from stretching a cubic lattice along two of its lattice vectors by two different factors, resulting in a rectangular prism with a rectangular base (a by b, which is different from a) and height (c, which is different from a and b). 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-centered
orthorhombic
| body-centered
orthorhombic
| face-centered
orthorhombic
|
| 
| 
| 
|
The point groups (or crystal classes) that fall under this crystal system are listed below, followed by their representations in international notation and Schoenflies notation, and mineral examples.
| name
| international
| Schoenflies
| example
|
| orthorhombic bipyramidal
| 
| D2h
| sulfur
|
| orthorhombic pyramidal
| 2mm
| C2v
|
|
| orthorhombic sphenoidal
| 222
| D2
|
|
