class=skin-invert-image, 180px, Triclinic (a ≠ b ≠ c ≠ a and α, β, γ, 90° pairwise different)
In
crystallography
Crystallography is the branch of science devoted to the study of molecular and crystalline structure and properties. The word ''crystallography'' is derived from the Ancient Greek word (; "clear ice, rock-crystal"), and (; "to write"). In J ...
, the triclinic (or anorthic) crystal system is one of the seven
crystal systems. A crystal system is described by three basis
vectors. In the triclinic system, the
crystal
A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macros ...
is described by vectors of unequal length, as in the
orthorhombic system. In addition, the angles between these vectors must all be different and may not include 90°.
The triclinic lattice is the least symmetric of the 14 three-dimensional
Bravais lattices. It has (itself) the minimum symmetry all lattices have: points of inversion at each lattice point and at 7 more points for each lattice point: at the midpoints of the edges and the faces, and at the center points. It is the only lattice type that itself has no mirror planes.
Crystal classes
The triclinic crystal system class names, examples,
Schönflies notation,
Hermann-Mauguin notation, point groups, International Tables for Crystallography space group number,
, type, and
space group
In mathematics, physics and chemistry, a space group is the symmetry group of a repeating pattern in space, usually in three dimensions. The elements of a space group (its symmetry operations) are the rigid transformations of the pattern that ...
s are listed in the table below. There are a total of 2 space groups.
With each only one space group is associated. Pinacoidal is also known as triclinic normal. Pedial is also triclinic hemihedral.
Mineral
In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2011): Mi ...
examples include
plagioclase
Plagioclase ( ) is a series of Silicate minerals#Tectosilicates, tectosilicate (framework silicate) minerals within the feldspar group. Rather than referring to a particular mineral with a specific chemical composition, plagioclase is a continu ...
,
microcline,
rhodonite,
turquoise,
wollastonite
Wollastonite is a calcium Silicate minerals, inosilicate mineral (calcium, Casilicon, Sioxygen, O3) that may contain small amounts of iron, magnesium, and manganese substituting for calcium. It is usually white. It forms when impure limestone or D ...
and
amblygonite, all in triclinic normal ().
See also
*
Crystal structure
In crystallography, crystal structure is a description of ordered arrangement of atoms, ions, or molecules in a crystalline material. Ordered structures occur from intrinsic nature of constituent particles to form symmetric patterns that repeat ...
*
Crystal system
References
* Hurlbut, Cornelius S.; Klein, Cornelis, 1985, ''Manual of Mineralogy'', 20th ed., pp. 64 – 65,
External links
*
{{DEFAULTSORT:Triclinic Crystal System
Crystal systems