Orthorhombic crystal system

File:Aragonit,8 Maroko.jpg

An example of the orthorhombic crystals, aragonite

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) and height (c), such that a ≠ b ≠ c. 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-centered orthorhombic	body-centered orthorhombic	face-centered orthorhombic
Orthohombic, simple	Orthohombic, base-centered	Orthohombic, body-centered	Orthohombic, face-centered

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	<math>\frac2mmm</math>	D2h	sulfur, olivine, aragonite
orthorhombic pyramidal	<math>2 mm</math>	C2v	hemimorphite, bertrandite
orthorhombic sphenoidal	<math>222</math>	D2	epsomite

See also

• Crystal structure
• Overview of all space groups

References

• Hurlbut, Cornelius S.; Klein, Cornelis, 1985, Manual of Mineralogy, 20th ed., pp. 69 - 73, ISBN 0-471-80580-7

Template:WikiDoc Sources