Search results
Results from the WOW.Com Content Network
Crystal structure [ edit ] Alabandite crystallizes in the cubic crystal system in the space group Fm3m with the lattice parameter a = 5.22 Å [ 5 ] and four formula units per unit cell .
Crystal systems that have space groups assigned to a common lattice system are combined into a crystal family. The seven crystal systems are triclinic, monoclinic, orthorhombic, tetragonal, trigonal, hexagonal, and cubic. Informally, two crystals are in the same crystal system if they have similar symmetries (though there are many exceptions).
Optical properties of common minerals Name Crystal system Indicatrix Optical sign Birefringence Color in plain polars Anorthite: Triclinic: Biaxial (-) 0.013
A crystal system is a set of point groups in which the point groups themselves and their corresponding space groups are assigned to a lattice system. Of the 32 point groups that exist in three dimensions, most are assigned to only one lattice system, in which case the crystal system and lattice system both have the same name.
The crystal structure of periclase corresponds to that of halite and has been studied extensively due to its simplicity. As a consequence, the physical properties of periclase are well known, which makes the mineral a popular standard in experimental work.
Trigonal crystal system This page was last edited on 5 April 2019, at 03:12 (UTC). Text is available under the Creative Commons Attribution-ShareAlike 4.0 License ...
Each crystallographic point group defines the (geometric) crystal class of the crystal. The point group of a crystal determines, among other things, the directional variation of physical properties that arise from its structure, including optical properties such as birefringency , or electro-optical features such as the Pockels effect .
Crystallography ranges from the fundamentals of crystal structure to the mathematics of crystal geometry, including those that are not periodic or quasicrystals. At the atomic scale it can involve the use of X-ray diffraction to produce experimental data that the tools of X-ray crystallography can convert into detailed positions of atoms, and ...